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MANUAL 



GENERAL, DESCRIPTIVE, AND PATHOLOGICAL 

ANATOMY, 

BY 

J. F. 1VJECKEL, 

Professor of Anatomy at Halle, &c. &c. &c- 

TRANSLATED FROM THE GERMAN INTO. FRENCH, 

WITH ADDITIONS AND N0TES, 

BY ■ 

A. J. L. JOURDAN, 

Member of the Royal Academy of Medicine at Paris, &c. &c. &c. 
and - 

G. BRESCHET, 

Adjunct Professor of Anatomy at the School of Medicine, &c. &c &c. 
TRANSLATED FROM THE FRENCH, 



WITH NOTES, 

BY A. SIDNEY DOANE, A.M., M. D. 



IN THREE VOLUMES. 
VOLUME I. 



PHILADELPHIA : 

CAREY & LEA.— CHESTNUT STREET. 



1832. 



V.I 



,m En ^ d *J C0 , rdi ?e,. t0 *. n act of Congress, in the year lbM, by Henry C. Sleleht in the 
office of the Clerk ol the District Court of the Southern District of New York." 



SLEIGHT AND ROBINSON, PRINTER! 

No. 1J1 Nassau St., New York. 



GEORGE C. SHATTUCK, A. M. ? M. D., M. M. S. 

OF BOSTON, 

THESE VOLUMES ARE RESPECTFULLY 

DEDICATED. 



. 



PREFACE 



OF THE AMERICAN TRANSLATOR. 



We feel ourselves called upon to state why the publication of 
this volume has been delayed so long : should we mention all 
the adverse circumstances which have retarded its progress, it 
would be matter of surprise to many that it appears now : but 
we shall not trespass upon the patience of the public, and will 
only plead in excuse, the magnitude of the work, the difficulty of 
procuring a copy of the original with which to compare the 
translation, and the labor of this revision ; as these difficulties 
are in some measure removed, the publication will proceed in 
future without delay ; in fact, the second volume is now in the 
press. 

In submitting our work to the profession, we claim their indul- 
gence ; we know it to be defective, and but illy fitted to meet the 
eye of criticism : a translation seems to be an easy thing : we 
advance no new theories, are responsible for no assertions, and 
are not bound to defend the opinions of the author : our object is 
merely to present his views with plainness and perspicuity : we 
may read, we may understand, but if we attempt to convey the 
meaning to others, unexpected difficulties are encountered. These 
are increased if the work be translated through the medium 
of a second language, and still more, if this medium, like the 
French of Meckel's manual, (we say it with high respect for 
those eminent men w T hose names appear on the title page,) be 
incorrect. Farther, a work of this character demanded a more 
able interpreter, some one whose name would have been a pass- 
port to its excellence : let it be remembered, however, that the 



AMERICAN PREFACE. 

manual has now been extensively known for six years; that 
during this time, translations have been announced both in Aitie 
rira and England, (in this country four to our knowledge,) and 
have been withdrawn, probably from the want of patronage, and 
we trust that our attempt will not appear presumptuous. 

In regard to the original, Professor Meckel's reputation as an 
anatomist, and a man of profound science, is immense ; his works 
are extensively and favorably known in Europe ; and of all 
scientific works in a foreign language imported into this country, 
no one has been circulated so extensively as the French transla- 
tion, which is now out of print. Farther, we have the written 
testimonies of some of the most eminent medical men in the United 
States, among whom we would mention Drs.Coates,(l) Horner,(2) 
Mott,(3) Physick,(4) Sewall,(5) J. A. Smith,(6) N. Smith, (7) 
Stevens,(8) and Warren,(9) (whose courtesy we take pleasure 
in acknowledging,) all of whom have been in the habit of 
referring to the work for years, and consider it one of the best 
treatises on anatomy ever written. We should not mention this, 
unless called upon by a passage in the preface to Cloquet's 
anatomy, translated by Dr. Knox of Edinburgh, and republished 
in this country ; a good translation of a valuable work. We 
quote the passage. Speaking of Cloquet, the Dr. says : " His 
omission of what is called ' General Anatomy,' with all its ab- 
surd theories, its tiresome diffuseness, its verbosity, and unprofita- 
ble minuteness, ought to be deemed by the student a great advan- 
tage, and a recommendation of the work ; and should any one 
doubt this, let him peruse the first volume of the ' Manuel 
d'Anatomie Generale, descriptive, et pathologique,' by J. F. 
Meckel, where he will find, under the title ' General Anatomy,' all 
the absurdities without the good sense contained in the l Element a 



(1) Physician to the Philadelphia Hospital. 

(2) Professor of Anatomy in the University of Pennsylvania. 

(3) Professor of Op. Surgery in the College of Phys. and Surg., New York. 

(4) Emeritus Profe-sor of Anatomy in the University of Pennsylvania. 
Hi Professor of Anatomy and Physiology in Columbia College, D. C. 

(6) Professor of Anatomy and Physiology in College of Phys. and Surg., N. York. 
I ofessor of Surgery in the Universi:y of Maryland. 

(8) Professor of Surgery in the College of Phys. and Surg., New York. 

(9) Professor of Anatomy atid Surgery in Harvard University, Boston. 



AMERICAN PREFACE. Vll 

Physiologic^ of Haller; and in addition, more idle, extrava- 
gant, unintelligible theories, misnamed anatomical, than ever yet 
were collected in a single volume." 

We should not expect, after this thorough condemnation of 
general anatomy without trial or jury, we had almost said with- 
out a judge, to find the Doctor employing his time and talents in 
translating a work on the same subject. One would think, too, 
that in guarding against absurd theories, absurdities stated as 
facts would have been avoided ; yet this is not the case. The trans- 
lation of Cloquet has been followed by that of Beclard's General 
Anatomy, into whichDr. Knox has introduced many strange things, 
not idle, extravagant, unintelligible theories, pardonable terms in 
regard to a favorite opinion, but statements professing to be facts, 
absolutely contradictory to common sense. (1) We admit that the 
French translation of Meckel contains assertions on one page 
which are contradicted in the next ; these, perhaps, may be found 
in our volumes, but a mere reference to the original will prove 
them to be errors of translation ; it is surely something new in 
criticism to attach the responsibility of these to the author, and if 
the position be tenable, we would only say — poor Beclard ! We 
respect Dr. Knox for his talents and information, but not for con- 
sistency,^) or for possessing that tone of kind feeling and liberal 
sentiment, which ought to exist between the educated men of 
every nation. 

We have admitted in the preceding paragraph, that contra- 
dictions occur in the French translation, which was evidently 
hurried : some of these errors are important to the student, and 
to correct them, our translation has been compared with the ori- 
ginal. Here, the translator and publisher would acknowk gc 
their obligations to Dr. Alfred C. Post, of this city, for his 
generous kindness in translating several notes and passages omit- 
ted in the French, and for the correction of several errors in the 
text ; but he is not responsible for those which may have passed 

(1) Such as comparing a muscle to a mitten! &c. For a nice dissection of Dr. 
Knox's translation, see the preface to the American version by J. Togno, M. D., 
published at Philadelphia, 1830. 

(2) We almost repent of this charge, more especially if the work was selected by 
the Doctor " with the consent of his publishers, as one worthy of transla.ion," and if 
the medical men on the other side of the Atlantic ever feel, as do many on this, the 
"wholesome stimulus of prospective want." 



Viii AMERICAN PREFACE. 

unnoticed. Dr. Post's opportunities have been great : the best 
advantages which our country afford, have been open to him : 
added to these, by residing in Fiance and Germany, and by at- 
tending lectures at the most celebrated universities he has acquired 
a good knowledge of the languages of those countries, and can 
command new sources of learning. The path of usefulness is 
now open before him, in which wc most cordially wish him 
success. 

We have endeavored in the American translation to present the 
meaning of the author faithfully : but we regret, that notwith- 
standing the utmost care in revising the manuscript and correct- 
ing the proofs, some errors are introduced ; the most important 
are noticed in our errata, and for them we would again ask 
indulgence. The volumes are already so large, that we have 
increased them only by adding such facts as have been observed 
since the publication of the French ; the original notes of Pro- 
fessor Meckel are designated by figures ; to those added by the 
French translator, the letters F. T. are attached : our own are 
marked with an asterisk* : for them we have depended on the 
medical journals, more especially the American Journal of the 
Medical Sciences, published at Philadelphia, whose Quarterly 
Periscope presents a brief summary of the discoveries made 
throughout the world. 

Hitherto, we have depended for our advance in the science of 
anatomy principally upon Europe. While the American practice 
of medicine combines the au vantages of the different European 
systems, and our medical men are not deficient in talents and ap- 
plication, the unjust and oppressive laws of our country exclude 
them from the study of anatomy. We say unjust and oppressive ; 
what can be more so, than to make a surgeon amenable to a civil 
tribunal for a professional error, while at the same time, if detected 
in attempting to gain the knowledge necessary to avoid those 
errors, he is exposed to fine, imprisonment, the stigma of public 
opinion, and the risk f being torn to pieces by an infuriated 
mob. We congratulate the profession, however, that the time 
is rapidly approaching, when the study of anatomy may be 
prosecuted in this country without the dread of the debtor's 
or of the state prison. Through the continued and well di- 
rected efforts of Dr. John C. Warren, the able Professor of 



AMERICAN PREFACE. IX 

Anatomy and Surgery in Havard University, the legislature of 
Massachusetts have finally passed an act legalizing the study of 
anatomy ; this act imposes additional penalties for violating the 
sepulchres of the dead, but at the same time it is all that any 
reasonable medical man can wish. Dr. W.'s exertions in the 
cause of science have been great, and this last effort, happily 
crowned with success, entitles him anew to the gratitude of the 
profession. We hope that the course of the legislature of Mas- 
sachusetts will be followed by the governments of the other states, 
and anatomy will then receive that attention which its importance 
demands. 

But we trespass upon the public, and will conclude with 
observing that no exertions shall be spared to render the suc- 
ceeding volumes of our translation worthy of their patronage. 



New Yohk, Nov. 10. 



Vol.. I. 



PREFACE 

TO THE FRENCH TRANSLATION. 



We have long wished for a work which should comprise all 
the important facts of General, Descriptive, and Pathological 
Anatomy, and of Physiology. A task so arduous demanded a 
knowledge both extensive and profound, and could be accomplished 
only by one of the first anatomists of the age. Meckel, who hono- 
rably sustains the medical reputation of his family, and to whom 
the world is indebted for several productions of merit, has fearlessly 
undertaken this laborious work. His treatise on anatomy is con- 
sidered as a standard in his own country, and will doubtless be 
favorably received in this. It is one of the finest productions of 
Bichat's school, Bichat, the envy of all Europe, and to whom 
Meckel has paid the most brilliant tribute of respect that talent 
can pay to genius, by professing for him a calm admiration. We 
have been careful in our translation to add all the new facts 
which have been discovered since the publication of the origi- 
nal.^) 

(1) Handbuck der menschlichcn Anatomie, Halle and Berlin. Vol. i. 1816. Gen. 
Anatomy. Osteology, Syndesraology, and Myology, Vol- ii. 1816. Angeiology and 
Neurology, Vol. iii. 1817. Sphlanclwology and Kmbrylogy, Vol. iv. 19-0. 











ERRATA. 






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GENERAL ANATOMY. 



MANUAL 

ov 

GENERAL, DESCRIPTIVE, AND PATHOLOGICAL 

ANATOMY. 



INTRODUCTION. 

I. Anatomy is the science of the organic form. This term is not 
very convenient, as it suggests only one of the numerous means em- 
ployed to attain a knowledge of the organism : hence, the terms zoo- 
gaphy, physiology, organography, and morphology, have been pro- 
posed as substitutes for it ; but as the word anatomy is sanctioned by 
long usage, and does not retard the continual progress of the science, 
it may be retained without inconvenience, and probably will be always 
used. , 

That series of practical rules by which we gain a knowledge of 
the organism, constitutes the art of anatomy. Its relations with 
anatomy are then those which exist between the means and the end. 

II. The particulars of the organic form are, 

1 . The external form, which may also be called the configuration ; 
it is determined by the relations which exist between the three 
dimensions. 

2. The inner form or the texture, (texlura,) the manner in which 
the body or its parts are composed. The term structure is also given 
arbitrarily to the composition of the. whole body, inasmuch as it is 
formed of large parts, while texture is applied to the composition of 
these parts, since they themselves are produced by the union of parts 
still smaller. 

3. The size. 

4. The color. 

5. The physical properties, the degree of cohesion, of elasticity, &c. 

6. The relation of locality of one part in regard either to the others, 
or to the whole body, and consequently, a. its situation, its place in the 
organism ; 6. its mode of connection with the parts adjacent. 

In the sketch of the organic form, we consider more or less com- 
pletely, 

Vol. I. 3 



18 INTRODUCTION. 

1 . The Chemical composition, and 

2. The properties and actions of the organisms, in order to present 
as complete a view as possible of all their characteristics. 

In fact, we may say that anatomy is to a certain extent the histori- 
cal part of physiology ; hence it would be convenient to consider these 
two sciences as forming but one, and to place them first in all books. 

III. The subject of anatomy is extremely varied ; it may then be 
presented in a great many different forms. 

IV. Thus: 

1. The science of the organization may comprehend a greater or 
less number of different organisms. The subject of anatomy, in gene- 
ral, is to make known the form of all the organs ; but the objects are 
so many and various, that it has been subdivided into phytotomy, 
or vegetable anatomy, and zootomy, or comparative anatomy. (1) In 

(1) The unity of the organic composition, the most important fact of animated na- 
ture, is now admitted by all enlightened naturalists. The meditative Greeks disco- 
vered it ; but when they studied it in detail, they objected to what were termed its 
numerous exceptions. This difference arose from the fact that Aristotle, and after 
him Galen, who have been followed by all anatomists, founded comparative anatomy 
on the unity of functions, because they knew not how to proceed, except upon per- 
fect organs, exercising determinate functions, and did not recognize identities, ex- 
cept in pursuing the insensible gradations of forms. An example will show better 
than abstract remarks the defect of this method, which prevented the unity of ana- 
tomy from being recognized, although that of the organic composition was admit- 
ted, and which determined the naturalists to make as many distinct systems of ana- 
tomy as they could perceive different characters. Take, for instance, the four limbs 
of a cat; they carry the trunk; they are the organs of support ; they are composed 
of moveable parts, which, put in action by the muscles, serve to move the trunk ; 
they are, then, the organs of locomotion ; they are terminated by moveable pha- 
lanxes, which extend and bend — these are the organs oiprehension, to seize and retain 
their prey ; finally, the last phalanx, which is naturally turned backward, can be 
brought in the same direction with the others, so that the sharp nails, which termi- 
nate it, project — they are the means of attack and defense. Now, if we consider the 
four limbs of the ape, we find they are capable only of the first three functions ; they 
perform only the first two in the dog, and the second in the seal. Their anatomical 
relations are, however, the same. Anatomy demonstrates, in the limbs of the cat, 
of the ape, of the dog, and of the seal, the same bones, the same muscles, the same 
ligaments, the 'same envelops, and the same nails ; they differ only in slight modifi- 
cations of form and size, to assist their uses. How then ought we to regard these 
forms, proportions, and functions'? 

Impressed with these great principles, J. St. Hilaire discovered, that to attach to 
anatomy a philosophical and truly scientific character, we must neglect the organs 
themselves, their too fugitive forms, and various functions, and consider only the or- 
ganic elements, which change or increase from new developments. In this manner he 
arrived at organic elements, which are, strictly speaking, the same, and discovered 
that the functions of the organs are much modified, according as some of their parts 
vary in length and thickness. Such is the path pursued by this naturalist, to give 
a philosophical turn to anatomy. His doctrine is, in fact, that of Aristotle, but with 
this important distinction, which gives it the character of a real discovery: Aris- 
totle did not recognize the analogy, except while the functions were preserved ; that 
is, he admitted no similarity when organs, composed of elements, employed these 
same elements, partly before, partly behind, or on the side ; in a word, directed them 
to other organs. Hence, a resemblance in form, and an equivalent destination 
assured him that the organizations were identical : in short, he mistook the appear- 
ance only for the rule. J. St. Hilaire does not say that the organs, but the materials 
of which they are composed, are always the same. This distinction changes the 
state of the question entirely, for then the identity remains a general fact even 
when the organs do not continue the same, as on leaving the classes. In fact it is 
only when the connections and mutual relations of two parts are similar, that'thev 
are analogous according to the new theory, which attaches but a secondary impor- 
tance to the different uses entailed by their newly acquired relations, and introduces 
for the first time in anatomy, the principle of the dissemination of the organic ma- 



INTRODUCTION. 19 

each of the two organized kingdoms, the science may treal particu- 
larly of a class, an order, a genus, or even a species. In fact, we 
must know the forms of all the species, to have a complete phytotomy 
or zootomy, and lastly, a complete anatomy. 

2. The limits of anatomy may also be contracted or extended, be- 
cause the organic form is not confined in each species by absolute 
rules, nor are all individuals formed after the same type. Thus : 

a. Anatomy is not the same at all periods of life : 

b. The two sexes differ from each other, at all ages, at least in the 
perfect species : 

c. The species comprehend a greater or less number of varieties, of 
races. 

There is then an anatomy of ages, sexes, and races : 

These differences may be considered as regular, inasmuch as they 
are constant, and necessarily belong to organized bodies. 

A second class of differences comprises the irregularities, so called 
either because they are not necessarily connected with the essential 
forms of organized bodies, and most of them arise more or less evi- 
dently by a departure of the formative act from the laws of formation, 
or because they endanger more or less imminently the existence of the 
organism. 

Pathological anatomy treats of these aberrations from the primi- 
tive type.(l) 

The anatomy of a species, to be complete, should comprise all the 
conditions above mentioned. We may, however, separate some of 
them from the rest, and consider them only. 

terials, which is so fertile in results ; by virtue of which these materials, when dis- 
placed, take on new actions, as do all those organs which have become rudimentary. 
Thus the doctrine of our learned compatriot is founded on the following : 1. That 
identity does not always depend upon the organs as a whole, but only on the mate- 
rials of which each is composed. 2. That inquiries after identity should regard the 
mutual, necessary, and consequently invariable, dependence of the parts. 3. That 
the organic elements which touch, are, from their position, necessarily constrained 
to assist one another reciprocally. 4. Finally, that an organ, whether in its normal 
or pathological state, never possesses extraordinary activity, unless some other one 
of the same system, or of those connected with it suffers proportionally, and in the same 
ratio. J. St. Hilaire briefly terms these the four fundamental laws of every organic 
formation, theory of analogies, principle of connections, elective affinities of the organic 
elements, and balance of organs. Regarded in this new light, anatomy will change 
the view of physiology, and will finally allow it to rank among the sciences ; it will 
even have a direct influence upon the practice of medicine ; for, first, it will estab- 
lish general pathology on a rational foundation, and refer to a single principle the 
many facts observed by pathologists, although ignorant of the law which embraced 
them all ; secondly, it will teach us to mistrust the experiments on animals, in 
which we have hitherto confided implicitly. Many physicians draw conclusions 
from these experiments in regard to man, saying, "the organs are the same, and 
consequently the functions must be similar." A blow from the claw of a cat, or the 
tiny hand of a child, would lead to an opposite conclusion. The stomach of the dog 
is unique like that of man ; but an enlargement in the size of its parts would change 
the nature of its functious. Will the dog then vomit, as man does? Be careful 
how you conclude. F. T. 

(1) Our idea of pathological anatomy would not be correct did we suppose, from 
the definition, it treated only of monstrosities, or of variations from the formative 
type ; for it makes us acquainted, also, with all the accidental alterations of the 
organic tissues produced by disease. Hence, to avoid all doubt, we say, that it 
treats of all aberrations from the primitive type, congenital or accidental. F. T. 



20 INTRODUCTION. 

The differences of the first class are not generally excluded from 
works which treat of the form in its regular state. It is to be regretted 
that the periodical differences arising from age are not usually suffi- 
ciently appreciated, being often very wrongly separated more or less 
from the anatomy, and considered as branches of a science with which 
they have no connection. On the contrary, the study of the normal 
state is often separated from that of the anomalies. This is also 
wrong ; first, because the line of distinction between the rule and the 
exception cannot always be exactly drawn. Secondly, because the 
anomaly is often a comment on the rule, and is a deviation only at the 
age when it is found. And finally, because, as anatomy proposes to 
give a complete view of the organic form, this end can be attained only 
by treating of every particular of this form. 

V. Anatomy may he presented in very different forms. Sometimes 
it is thought sufficient to describe successively the organized bodies as 
a whole, and in detail ; sometimes general results are deduced from 
these isolated descriptions; in order to obtain directly a knowledge of 
the peculiarities which distinguish the different tissues which compose 
the organism, and the general laws according to which the organic 
form seems to have been produced. 

Hence anatomy is divided into two parts, according as it treats of a 
single species of animals, or embraces all organized bodies, into general 
and special, or topographical anatomy. 

The first comprises the general conditions of the organisms, and the 
union of the parts which form them : the other is confined to their 
details. The first acquaints us with the different systems composing 
the organism, the other learns us the distinctions between the different 
parts of the same system. The former pertains rather to physiology y 
the latter to surgery ; but the second is indispensable to the physiolo- 
gist, as .the first is to the surgeon. 



GENERAL ANATOMY. 



SOURCES. 

The sources of general anatomy, are all the works on general anato- 
my, and on physiology, as well as on the different branches of the former ; 
since we there find an exposition, more or less exact and complete, both 
of the general properties of the organic formation, as of those of each 
of the systems which unite to form the organism. 

Under the first head we recommend several chapters of the first 
volume of Dumas (Principes de Physiologie, Paris, 1806 ;) under the 
second, Haller's (First lines of Physiology,) Bichat, (General Anatomy, 
Boston, 1822,) with Beclard's additions, and Soemmering, (Lehre vom 
Baue des menschlichen Kozrpers, Frankfort, 1800.) The last is men- 
tioned, principally, for the general conditions of most of the organic 
systems, particularly the bones, ligaments, muscles, nerves, and vessels. 
In most of these works, the healthy and unhealthy state of the parts 
are considered at the same time, but without saying all that can be said 
upon the latter topic, and without always ascribing to it the importance 
it merits. Portal (Anatomie medicate, Paris, 1804,) has treated all the 
organized systems in both of these states on a good plan. 

The French anatomists have, generally, described pathological altera- 
tions in their treatises before the writers of other nations. Munroe's 
book (Outlines of the Anatomy of the Human Form, London, 1813) is 
an exception to this remark. 

The principal treatises on the alterations of textures, and of the struc- 
ture of the human body, and the most important for exact descriptions, 
and the great number of facts tending to establish the systems of patho- 
logical anatomy on a firm basis, are those of 
Morgagni, (De caus. el sedibus morb.) 
Baillie, (Morbid Anatomy of the Human Body, 1793.) 
Voigtel, (Handbuch der pathologischen Anatomie, Halle, 1804,) and 
Mechel, (Handbuch der pathologischen Anatomie, Halle, 1813.) 
The principal works upon each part of general anatomy will be 
mentioned hereafter, when treating of those parts. 



GENERAL ANATOMY. 



PART I. 



GENERAL LAWS OF FORMATION. 

§ 1. The human body, as well as all those that resemble it, is com- 
posed of various parts, which have the mutual relations of preservation 
or of generation, and which reciprocally play the part of means and 
end, one with the other, and of which the actions, infinitely varied, have, 
for a result, life, and the preservation of every thing formed by their 
union. 

§ 2. These parts are so different inform, chemical composition, phy- 
sical and vital powers, and the phenomena dependent upon them, that 
it is much easier to point out their differences, than their analogies. 
Nevertheless, when the thing is examined attentively, we can mention 
certain general qualities, in regard to all the conditions above, so that 
these considerable differences then seem to be only simple modifications 
of a single and even primitive type. 

§ 3. The organic form, consequently also the human form, presents 
two points of view : 1st, its intimate composition, the texture of its 
parts ; 2d, the external composition, the structure or the form. But 
when closely regarded, it is seen that these two points differ only in 
degree. 

§ 4. As regards texture, the component parts may be reduced to 
others more simple, which in their turn differ from each other, in their 
degree of simplicity, and may, therefore, be divided into proximate and 
remote. 

§ 5. The remote constituent parts of the organic form, are finally 
reduced to two, of which one appears constantly under a given form 
which is not the case with the other, although this is equally suscep- 
tible of figure. These parts are the globules and a coagulated or co- 
agulable substance. The part is solid or liquid, according as the latter 
in the first or second state, exists alone, or with globules, and it has an 
external form in the former case. All the solid and fluid parts do' not 
contain these last two constituent materials : but the globules never 
exist alone ; they are always imbedded in a coagulated or coan-uJable 
substance. 

§ 6. The term globule is not well adapted to corpuscles having a 
definite form ; for it is proved that many of them, particularly the glo- 



GENERAL LAWS OF FORMATION. 



23 



bules of the blood,(\) are not equally thick in all directions, but are flat 
and lenticular, since, if rolled on an oblique surface, their edges may be 
seen with a microscope. (2) They are however never angular, but 
always rounded, and vary in form, size, number, color, and chemical 
composition, not only in different subjects and in different parts of the 
same subject, but even at different stages of life, whether they pass or 
return, and are regular or irregular. 

Thus, in regard to form, the globules appear more complicated in 
some parts than in others. In the blood, according to the best authori- 
ties, they are formed of a central part, which is solid, and of an 
external part, which is hollow, vesicular, and incloses the first, but does 
not adhere to it. Every where else their structure appears more sim- 
ple, for one only of these two parts is perceived ; but whatever may be 
the region of the body in which they are examined, their general form 
appears the same in the same animal, that is, they are never found ob- 
long in one part, and rounded in another. In man they are rounded. 

The globules differ much in volume in the different parts of the 
body : they are smaller in the liver than in the kidneys, and larger in the 
spleen than in the liver. (3) Those of the nervous system aie smaller 
than those of the blood ;(4) these latter are in their turn larger than those 
of the lymph, of milk, and of chyle. (5) At the commencement of sup- 
puration^) they are smaller than when it has existed for some time.(7) 

(1) C H. Schultzhas very recently attempted to demonstrate that blood endowed 
with the vital principle is not composed of globules swimming- in serum, but forms a 
homogeneous mass, which is divided into numerous corpuscles, exercising, upon 
each other and on the parietes of the blood-vessels, the most lively action ; so that 
they are reciprocally drawn together, or rather are united, and then reform them- 
selves anew : they attract each other mutually, and join to form one mass : this 
mass resolves itself into several parts ; and the same thing occurs again. I his new 
theory of the vitality of the blood founded on microscopic observations, if confirmed, 
will have a powerful influence on physiology, and will serve to explain the existence 
of animal scions, which have been rejected too soon, because we could not understand 
them See two important memoirs of Schultz in the Journal Complementaire : 
Observations microscopiques sur la circulation du sue propre dans la chehdoine et dans 
plusieurs autres plantes, vol. xvi. p. 208. and vol. xvii. p. 136. Memoire sur lespheno- 
menes de la vie dans le sang, demontrcs par les observations microscopiques, vol. 
xix pp 19 and 212. The observations of this physician have been resumed by Du- 
troc'het who thinks they were founded on an optical delusion.— Same Journal, vol. 
ix p 289 This subject demands more attention, and we invite to it the talent and 
zeal 'of physiologists. We ought, however, to add that Dcellinger {Was ist Abson- 
derung und wie geschieht sie, Wurtzburg, 1819, p. 21.) had already rejected the 
thooryof globules swimming in serum ; but he admits the existence of globules : he 
thinks too that the blood should not be termed a fluid ; for it does not run like 
water, but like the fine sand contained in an hour-glass. F.T. 

(2) Hewson, Experimental Inquiries, London, 1777, vol. m. p. 15. Leuwenhceck 
says they are globular in man and the mammalia, but flat in fishes.-Mrc. Nat. vol. i. 
p 51 ) Schmidt states they are round in man and the mammalia, and elhptically ob- 
lono-'in all other animals.— (Sur les globules du sang, in the Journal Compl duDict. 
des^Sciences Med. vol. xviii. pp. 107 and 210.) See also the work of G A. Magni, 
(Nuove osservazioni microscopiche sopra le molecule rosse del sangue, Milan, 177b,) 
as likewise that of Prevost and Dumas, (in the Bibliotheque Vniverselle, 1821, July, 

'(I)" Wenzel. Prodromus eines Werks uber das Gehcrn des Menschen und der 
Sceugthiere, Tubingen, 1806, chap, iv 

(4) Prochaska. De Struct. Nerv. Vienna, 1779, chap. iv. 

(5) Hewson. Exp. Inq. tabs. 1 and 4. 

(6) Home. On the Properties of Pus, London, 1778, p. 14. 



(7) M Edwards from his microscopic researches upon the cellular, fibrous, and 
vascular tissues, the muscles, and the nervous tissue, or pulpy substance of the brain 



34 GENERAL ANATOMT. 

Some fluids, as urine, contain very few globules ; the same is true of 
some solids, as the mucous tissue, the fibrous parts the cartilages, the 
bones. On the contrary, there are more in the blood the muscles, and 
the nervous substance. More are found in the blood than in chyle and 
milk ; they are also more numerous in perfect pus than in that which 
is just forming. . 

The color and chemical composition of the globules are determined 
usually by those of the parts ; since the latter are constituted by them, 
and they cause the differences of the parts. This proposition appears 
incontestible, at least as regards the solids. 

In all these respects the globules are subject to periodical changes. 
The analogy between man and animals renders it probable that at 
different periods of life they vary considerably also in him, both as 
regards form and volume ; for in the fetuses of birds and reptiles, glo- 
bules of blood have been found of another form and much larger than 
in the adults. The same remark is true in respect to color and chemi- 
cal composition ; since the two qualities do not remain the same in the 
same parts at all periods of existence. Their number certainly 
changes regularly at different times. At the commencement of the 
first period, when the fetus is forming, no globules can be perceived, 
and the substance of the new being is composed entirely of a coagu- 
lable, homogeneous liquid ; this soon separates into a fluid part and 
another which is more consistent ; the latter is surrounded by the for- 
mer, and, as a plate of zink moistened with water, is alternately in 
a positive or negative state of electricity, according to its situation, so 
the positive state every where prevails in the solid portions, or the glo- 
bules, and the negative, in the liquid which surrounds them. But 
when the fluid, which was at first homogeneous, once divides into glo- 
bules and a liquid, the globules . continue for some time more apparent 
than they are afterwards, and then may be discerned in all parts of the 
fetus. 

§ 7. These two remote constituent parts, the globules and the coagu- 
lable liquid, produce, either the second alone, or both combined, two 
principal forms : in the first, the length much exceeds the other dimen- 
sions ; in the second, it is more nearly equal to the breadth, although 
they both exceed the thickness. The first form is called fibrous, the 

i 

and nerves, has determined that the elementary parts of these tissues are formed and 
arranged in the same manner in every animal observed by him. Edwards thinks 
he can establish, as a general law, that the proper elementary structure of these dif- 
ferent tissues is the same in all animals. A still more remarkable fact is developed 
by his researches, viz., that the form and size of the globules are always the same, 
whatever is the organ or animal in which they are examined. We must then believe 
that the primitive form of the molecules of solid and organized animal matters is 
always constant and definite. In fact, as Edwards states, the organic tissues above 
indicated are formed of spherical corpuscles ? £^ of a millimetre in diameter, what- 
ever may be the other properties of these parts and the functions for which they are 
designed.— (H. M. Edwards. Memoire sur la structure elcmentaire des vrincipaux 
tissus organiques dc I'homme, Paris, 1823.) F. T.* 

* M. Raspail concludes, from some recent microscopic observations, that the mem- 
branes, when isolated, and reduced to their proper consistence, are not composed of 
globules perceptible by our means of observation, and however coarse those exa- 
mined may be, their surfaces appear smooth, and not granulated.— Am. Med 
Jour. Nov. 1828, from the Repertoire d' Anatomic 



GENERAL LAWS OF FORMATION. 25 

second, the laminar : the fibrous form belongs usually only to the coagu- 
lated liquid, which is sometimes changed into fibres, even without the 
globules, as in the bones, tendons, &c. 

The globules tend very much, with the coagulable liquid, to form 
fibres ; that is to say, to arrange themselves one after another, as is 
seen in the nervous and muscular systems ; although in several parts, 
as in the substance of the viscera, they are deposed without any regu- 
larity, being placed indiscriminately in the coagulable fluid. The latter 
is, however, inseparable from the globules, for it envelopes them entirely: 
even the most delicate fibres are surrounded with a sheath, produced 
by this fluid, in which all the parts are, in some measure, placed, and 
in the liquid portions of which, the globules contained in the fluids float. 

The properties of the fibres vary as much as those of the substances 
which constitute them. There is, then, no single or elementary fibre. 

§ 8. The union of fibres and laminae, or of the latter alone, produces 
spaces of different forms, called cellules. Gallini, Ackermann, and some 
others, were wrong in considering these cells as the only final elements 
of form. The very expressions of these authors refute their own 
opinions ; for if " all the parts of the body are aggregations of laminae 
of different sizes, joined one to another at different angles, so as to inter- 
cept between them, spaces or cells of various sizes,"(l) or if "four 
mucous laminae joined at an acute angle, enclosing a space called a 
cell, are the homogeneous elements of every organization,"(2) it is 
easy to perceive, that the cellular formation comes manifestly from the 
lamellar, and thus that the cells are a secondary formation. To this it 
may be objected that the globules are, properly speaking, cells, and 
hence that the fibres themselves are composed of cells ; but this opinion 
cannot be admitted, because these globules exist in a loose state in the 
fluids. Besides, there are many parts in which there are no traces of 
these hypothetical cellules, and which appear to be produced by a ho- 
mogeneous fluid coagulated in large laminae, as is seen particularly 
in the serous membranes. It is equally improper to call the fibres 
the crystaline forms of organized bodies. (3) 

§ 9. In the body the fibrous formation exceeds the lamellar very 
much, and the parts themselves in the whole form in which the 
dimensions of length and breadth are equally developed, such as the 
fibrous membranes, the broad bones and muscles, manifestly exhibit 
the fibrous texture internally, a circumstance belonging, unquestion- 
ably, to the law, in virtue of which the dimension of length, in the 
whole body, exceeds the other two. The fibres are easily distinguished 
in the nerves, muscles, most of the bones, and the fibrous organs. A 
tissue, at once fibrous and lamellar, is found in the viscera,and partially, 
also, in the bones. 

§ 10. These elements, disposed in fibres and laminae, which originally 
differ much in figure and composition, produce, when united, several proxi 
mate or immediate constituent parts of the form, which vary considerably, 

(1) N. Gallini, Betrarhlv.ngcn iieber die neuen Fortschrittc en der Kennlniss des 
Menschlichen Kcprpers, Berlin, 1794, p. 61. 

(2) Ackermann, Darstellung der Lehrc von den Lebenskrwjtcn, vol. i. p. 11. 

(3) Autenroith, Physiologic, vol. i. p. 7. 

Vol. I. 4 



26 GENERAL ANATOMY. 

both m their internal and external figure. These bodies have received 
the name of systems, in relation to their form, by which we understand, 
that the different parts of a given combination resemble each other, and 
differ from the others in all the parts of the body. Many, as the mu- 
cous, nervous, and vascular systems, deserve this term m a still more 
special manner, because they form an uninterrupted whole. Here the 
connection is less intimate in some systems than in others ; for example, 
the bones and muscles do not offer, like the above mentioned, an unin- 
terrupted continuity in their proper substance ; nevertheless, they are 
so united into a whole by peculiar systems, to wit the fibrous, that the 
periosteum which covers the bones, not only has the same structure 
as the accessory ligaments which pass from one bone to another, and 
as the tendons of the muscles which are inserted into it, but also 
forms with them a continuous whole. 

Other parts of the body, on the contrary, as the viscera, and serous 
membranes, are isolated, and are retained, one to the other, only by the 
first three systems, which are universally diffused, and form an unin- 
terrupted whole. 

The different parts of the body receive also the name of tissues, (tex- 
lus,) in regard to their internal structure ; and that of organs, by reason 
of the actions they execute ; for each acts, in its manner, for the pre- 
servation of the body, which is itself called an organism, in reference to 
the activity of the parts constituting it. 

§ 11. These different parts vary much from each other, in their ex- 
ternal and internal form, their chemical composition, their mode of vital 
activity, and their functions. They differ most, however, in the degree 
of complication. There are, in this point of view, two grand princi- 
pal classes, which may be called, the first, the class of simple organic 
organs or systems, or of similar parts, {partes similar es,) because 
they are found in the body more than once ; the second, the class of 
compound organs or systems, or of dissimilar parts, (partes dissimi 
lares,) or as Bichat terms them, of apparatus, because they are found 
in the body only once, or at most twice. The union of the simple or- 
gans takes place in a determined manner, many of them uniting to 
give rise to parts designed to accomplish a special function, single, 
or at most double. Combining thus, they form the apparatus ; so 
that the body, considered as a whole, results from an assemblage of 
compound systems which we must decompose and reduce to their 
elements, if we wish to have an exact and complete idea of the condi- 
tions of their existence. The hand, the foot, each viscus, the different 
organs of the senses, &c. are examples of these apparatus. Neverthe- 
less, v/e should observe, that the fine of demarkation between the sim- 
ple and compound organs is not rigorously traced. The simple organs 
themselves are composed of several different parts, and combine and 
unite differently. As for the more complicated organs we can with 
attention, refer them to simple systems, since we finally find, in several 
the same conditions which are presented by the latter. This is the case' 
at least with many of them, and particularly with those termed viscera • 
doubtless all these do not differ from other parts, sufficiently to consti- 



GENERAL LaWS OF FORMATION. 27 

lute special organs ; but when examined attentively, we ascertain, 
first, that they are only simple modifications, or branches of one and 
the same system, the cutaneous ; and secondly, that they are so analo- 
gous to the vascular system, that no perfectly distinctive characters can 
be assigned to them : both are canals having their parietes formed essen- 
tially of two layers, an internal and an external, of which the latter tends 
to move the contents, and which are both formed with vessels and nerves. 
We are then embarrased in attempting to decide on the subject of cer- 
tain parts, whether they should be regarded as simple or compound 
organs. The skin, for instance, is certainly an apparatus, a compound 
organ, if we consider it in its totality, as is necessary to acquire an 
exact idea of its functions : but, we can distinguish in it several particu- 
lar systems, since we can reduce it mechanically, not only to parts 
which are found in other organs, but into those which are peculiar to 
it, as the cutis, papillary tissue, epidermis, hair, and nails. 

§12. We ought not, however, to think, from what has been said, 
that a classification founded on the difference of tissue and of compo- 
sition, is useless and impossible ; on the contrary, it appears more pro- 
per, not only to examine the simple and compound organs separately, 
but farther, in making the table of the most simple systems, to consider 
all the parts manifestly connected with a compound organ, as belong- 
ing to this organ, and to describe them with the others, rather than fol- 
low the opposite coarse, and to refer the history of these different parts 
to that of the simple systems to which they belong. This method is 
decidedly the best, at least for those systems which do not form an en- 
tire whole, as the vascular and the nervous systems. 

§13. The number of systems should be determined after a profound 
study of the properties possessed by the different parts ; since we must 
admit as many particular systems as we can demonstrate different tis- 
sues. But at the same time we must be careful to refer to the same 
system, all the parts which resemble each other in these different points 
of view, however great may be the distance between them. 

§14. To approach the truth as nearly as possible in this respect, we 
must clearly distinguish the final forms and the final tissues, to which 
all the formations are reduced, that is, the laminae and the fibres, from 
the forms which proceed from a particular arrangement of the latter, 
and which appear to constitute so many distinct species, because each 
of them has less analogy with all the others than exists between those 
of their parts, which are found in different regions of the body. Suffi- 
cient attention is not generally paid to this difference ; hence why the 
forms of the second species have been united with those of the first. 

Haller(l) and some other physiologists admit only three tissues, to 
which all the others are referred ; these are the muscular fibre, the 
nervous fibre, and the mucous tissue. They assert that all the organs 
which are not formed from the first or second of these fibres, belong to 
the third division. 

This resembles the division of those authors who admit three primi- 
tive forms: 1, the cellular, or membranous; 2, the vascular, or 

(1) De part. eorp. hum. vol. i. p. 46. 



28 GENERAL ANATOMY. 

fibrous; and 3, the nervous. (\) These two classifications have the 
same defect, for if, in arranging the first elements, only the difference of 
texture is considered, the number of divisions is too great, since the ner- 
vous and vascular formations belong evidently to the same class, that 
of the fibrous organs. But if we attend to the specific differences of 
the external and internal form, and of the actions, these two classifi- 
cations are insufficient, because the number of the forms and of the 
modifications of the vital phenomena is much greater. 

The classification of Dumas(2) is more correct ; he admits four tis- 
sues ; the cellular, or spongy ; the muscular, or fibrous ; the mixt, or pa 
renchymatous ; and the lamellar, or osseous. The first three represent 
truly the primitive form, although the term muscular, given to the 
second, is badly chosen ; but the fourth should be rejected, as the 
osseous tissue evidently belongs to the second class. 

§15. Nevertheless, as these classifications announce only the primi- 
tive forms, and consequently may be referred to what has been stated 
above, (§7,) they are far from removing the differences pointed out 
between the particular systems. It is less correct also to derive cer- 
tain systems from others, and hence to regard them as modifications, 
than to say, certain systems are extended more generally than others, 
and contribute to their composition and preservation, while they do not 
exercise a similar influence upon them. 

With these ideas, Bichat has formed his general anatomy, although 
his classification is not perfectly correct. He admits general systems, 
andparticular systems; the first, which are also called generative, because 
they are generally distributed, and concur to form all the others, are six 
in number: the cellular, or mucous, the arterial, the venous, the exhalenf, 
the absorbent, and the nervous systems. (3) He has even increased this 
number by one, having subdivided the nervous system into the nervous 
system of animal, and that of organic life. If we unite, as should be 
done, the second, third, fourth, and fifth, we reduce the systems to three, 
the mucous tissue, the vascular system, and the nervous system, which, 
adopting Bichat's meaning, might be called primitive, or general sys- 
tems, but to which this name is not applicable when we confine our- 
selves to the acceptation universally received. 

Besides these three, we usually establish but a small number of sys- 
tems, because the general characters of the tissues, in different parts of 
the body, are neglected, while other tissues, which are composed of very 
different elements, are considered as primitive ; and, in tracing their 
history, we describe the different parts which concur to form them but 
without reflecting that several of these parts, although they do' not 
form a connected and coherent whole, and often differ, even in their 
external form, do not the less belong to one and the same system 
when their most essential properties are considered. Thus a 
muscle is described as composed of a fleshy and of a fibrous portion 
without thinking that the first alone enters into our idea of what a 

(1) Walther, Physiol, vol. i. p. 97. 

(2) Prop, de, phys. vol. ii. p. 4. 

(3) Bichat's General Anatomy, trans by (J. Hayward, vol. i. p. 79, 



GENERAL LAWS OF FORMATION. 29 

muscle should be, and that, the second belongs not to the muscle only, 
but also to other and very different parts. 

Other systems are then referred to the bones, cartilages, ligaments, 
muscles, and viscera. Hence anatomy is divided into osteology, to 
which is joined chondrologij, as most of the ligaments are blended with 
the bones, syndesmology, myology, splanchnology, angiology, and neu- 
rology. Nevertheless, this division does not exhaust, by any means, 
the subject of anatomy. The bones, cartilages, ligaments, muscles, 
and viscera, are, it is true, essentially different organs : but, first, the 
class of ligaments is faulty for two reasons : because it comprehends 
two kinds of different tissues, on the insufficient ground merely that 
both extend from one bone to another ; secondly, because there are 
several organs, which deserve, as much as the ligaments, to be admit- 
ted to that class, even after rectifying it, as it might be amended. 
Again, the class of viscera, which may safely be called a negative 
class, embraces organs so dissimilar, that no general characters can be 
assigned it ; and we know not how to retain it, at least, as we do not 
wish to give it the name of the class of the most complicated organs or 
apparatus. 

§ 16. Here we cannot overlook the services which Bichat has ren- 
dered to anatomy, regarded philosophically, and as a science, although 
we must admit he has made too many classes.(l) He mentions fourteen 
besides the generative systems, (§ 15,) viz : 1, the osseous system : 2, the 
medullary system : 3, the cartilaginous system : 4, the fibrous system : 

5, ihe fibrocartilaginous system : 6, the muscular system of animal life : 
7, the muscular system of organic life : 8, the mucous system : 9, the se- 
rous system : 10, the synovial system : 11, the glandidar system : 12, the 
cutaneous system : 13, the epidermoid sijstem,<xnd 14, the pilous system. (2) 

Among these systems, we suppress the medullary system, which is 
the same as the cellular tissue, and the synovial system, a slight modi- 
fication of the serous system : the two muscular systems should be 

(1) Bichat gen. anat., Vol. ii. p. 141. 

(2) It may be well to mention how modern physiologists and anatomists have di- 
vided the organic tissues since Bichat. 

Walther thinks that all the tissues are derived fromjthe cellular; and t hatthey proceed 
from this primitive tissue in two series : one comprising the serous and synovial 
membranes, the mucous membranes and glandular lissue, the dermis, epidermis, the 
horny and pilous tissues : the other, the muscular tissue, the fibrous membranes, the 
fibro-cartilages, the cartilaginous, and osseous tissues.— (Darstellung des BichaV- 
schens systems : in Schelling and Marcus, Jahrbuchen der Mcdicin.) Vol. ii. P. i. 
p. 49. 

Dupuytreyn has diminished the number of tissues admitted by Bicliat, and has add- 
ed one very important, which Bichat had omitted : \,ihccellular-systcm:2, thevascular 
system, arterial, venous,a.nd lymphatic : 3, the nervous system,cerebral ',and ganglionic : 
4, the osseous system : 5, the proper fibrms system, fibrocartilaginous, and dermoid : 

6, the muscular system, voluntary and involuntary : 7, the erectile system. : 8, the 
mucous system : 9, the serous system. : 10, the horny system, pilous, and epidermoid : 
1 1 , the parenchymatous system, properly so called, and the glandular. 

Chaussier divides thepartsof the animal body as follows : 1, the bones : 2, the articular 
cartilages, of prolongation, of ossification : 3, the muscles: 4, the ligaments: 5, the 
vessels: 6, the nerves : 7, the vascular ganglions, glandiform bodies : 8, the simple folli- 
cles, or crypts, proximate, compound: 9, the lachrimal,salivary, and mammary glands, 
thepancreas, liver, kidneys, and testicles : 10, the larrtellar, muscular, albugineous, sim- 
ple villous, or serous, compound villous, or follicular, and coriaceous membranes, and 
epidermis : 11, the lamellar or cellular : 12, the viscera, the digestive respiratory, circu- 
latory, urinary, and genital organs, and those of the senses.— ( Table synoptiques des 
soiides organiques.) 



30 GENERAL ANATOMY. 

United. Wo ought not to separate the fibrous system from the epi- 
dermoid system, which, perhaps, should be joined to the dermoid sys- 
tem. Finally, all the probabilities authorize us to unite the dermoid, 

It. Cloquet admits fifteen tissues, viz : cellular tissue, membranes, vessels, bones, car- 
tilages, fibro-cartilages. ligaments, muscles, tendons, aponeuroses, nerves^glands, 
follicles, lymphatic ganglions, and viscera.— {OoqueVs Anatomy, Boston, 1830.) 

Lenhossek numbers only eight tissues : 1 , the cellular tissue : 2, (he mucous, serous, 
fibrous, and mixed membranes: 3, the cutaneous system, including- the epidermis, 
nails, and hair : 4, the vascular, arterial, ramus, capillary, and lymphatic system: 
5, tlie nervous system : G, the muscular system : 7, the glandular system: 8, the os- 
seous system, with the cartilages and the medulla. -(Physiologia medicinalis.) 

Mayer also admits eight : 1, the lamellar, or albugincous tissue, tissue of the crys- 
taline and cornea, epidermis, hair, and nails: 2, the cellulo-fibrous, cellular, adipose, 
medullary,serous,synovial tissues, and that of the vascular membranes, dermoid system, 
system of the mucous network, tissue <f the uterus : 3, the fibrous tissue, proper mem- 
branes of the glands, of the spleen and kidneys; albugincous membrane of the testicles, 
tissue of the corpora cavernosa, tissue of the sclerotica, of the dura-mater, and of the 
periosteum, the perichondrium, fibrous articular capsules, ligaments, aponeuroses, 
tendons, neurilema : 4, the cartilaginous tissue of organic life, or fibro-cartilagc, 
that of animal life, or articular cartilage : 5, the osseous tissue : 6, the glandular 
tissue: 7, the muscular tissue, and, 8, the nervous tissue. — (Ueber Histologic und 
eine neue Eintheilung dcr Gewebe des menschlichen Kcerpers, Bonn, 1819.) 
Rudolphi divides the solid parts into simple and compound. The simple parts are : 

1, the cellular tissue : 2, the horny tissue, which comprises the epidermis, epithelium, 
nails, and hair: 3, the cartilaginous tissue: 4, the osseous tissue: 5, the tendinous 

fibre : 6, the vascular fibre : 7, the muscular fibre : 8, the nervous fibre. The 
compound parts are': 1, the vessels, both general and special; the former com- 
prising' the arteries, veins, and absorbents, and the latter, the special canals of the ex- 
cretory organs, as the biliary, salivary, urinary, and seminal ducts : 2, the mem- 
branes, which are also divided into general, as the serous, mucous, and fibrous, the 
dermis and epidermis; and special, as the membranes of the ovum, of the eye, and 
encephalon : 3, the viscera : \, i\ieglands. — (Grundriss dcr Physiologic, Berlin, 1821.) 
See alsoC. A. Rudolphi, Programmade corporis humanipartihus similaribus, Grisp- 
wald, 1809 ; and S. J. Bugaiski, Dissertatio dc partium corporis humani solidarum 
similarum abcrrationibus, Berlin, IS 13. 
J. Cloquet classes the tissues of the human body as follows : 1, the cellular system : 

2, the adipose system : 3, the vascular system : 4, the nervous system : 5, the serous 
system : 6, the mucous system : 7, the ligamentous system : 8, the elastic system : 
9, the cartilaginous system : 10, the fibrocartilaginous system : 11, the osseous sys- 
tem : 12, the muscular system : 13, the erectile, or cavernous system: 14, the glan- 
dular system : 15, the horny system. — (Anatomic de Vhomme, ou Description et figures 
lithographies de toules I es parties du corps humain, Paris, 1821.) 

Heusinger refers all the organic tissues to eleven : the formative, or cellular, the 
horny, the cartilaginous, the osseous, the fibrous, the membranous, the nervous, the 
serous,the vascular, the parenchymatous, and the glandular. — (Syste7n der Histologic, 
Eisenach, 1822.) 

Ducrotay de Blainvillc admits a generative clement, the cellular, or absorbent 
tissue, and two secondary elements, (he muscular, or contractile fibre, and the ner- 
vous, or exciting fibre. By slight modifications, the cellular tissue produces nine 
systems : the dermoid, mucous, fibrous, fibro-cartilaginous, and cartilaginous osseous 
serous, synovial, arterial, venous, and lymphatic. The first secondary element pro- 
duces three systems, the subdermoid muscular, submucous muscular, and the pro- 
found muscular ; and the second secondary clement forms four : the pulpous °-on- 
glionic, the apulpous ganglionic, the nervous system of animal life, and the nervous 
system of organic life. — (Principcs d' Anatomic comparcc, Paris, 1822.) 

Beclard admits 11 classes of tissues: 1, the cellular and adipose tissue : 2 the 
serous membranes : 3, the tegumentary membranes : 4, the vascular By stem': 5' the 
glands: 6, the ligamentous tissue: 7, the cartilages: 8, the osseous system : 9 the 
muscular system : 10, the nervous system : 11, the accidental for motions.— {Elernens 
eP "anatomic generate, Paris, 1823.) 

We may also consult, in regard to similar parts, or simple (issues of the animal 

economy, Fallopia, De parttbus ■similaribus humani corporis, Nuremburs 1575 

Malacarae, I sistemi e la loro reciproca influenza indagati, Padua, 1803 T'roc.h' 
ka, Bemerkungen uber den Organi nschlichen Kcerpers Vienna IRKvfl 

Mascagni, Prodromo delta grande Anatomia, Florence, 1819 : Milan I82l4v I 

'P. T S ' 



GENERAL LAWS OF FORMATION. 



31 



muscular, and glandular systems. Thus the twenty-one systems ad- 
mitted by Bichat, are reduced to twelve, and even to ten, viz : the mu- 
cous, vascular, nervous, osseous, carlilaginous, fibrous, fibrocartilagi- 
nous, muscular, serous, and dermoid systems.(l) 

These will be examined in the general anatomy, according to their 
general conditions, and in the special anatomy, topographically, or ac- 
cording to their local relations ; when the general considerations of the 
organic form, including the human form, shall have been first given. 

§17. The general laws of the organic form, and hence those which 
belong *o man, are as follows : first, the outline is not sharp and angu- 
lar, but rounded. This law is true, both in regard to the form of the 
whole body, as well as to that of each of its organs, and its smallest 
elements. The roundness of the form usually depends upon the fact, 
that all the solids are accompanied with fluids, for the first effect of so- 
lution is to smooth down the angles of solid bodies. We mention, as 
examples, the round form of the cavities of the body, of the viscera, ves- 
sels, nerves, muscles, bones, &c. 

§18. II. The dimension of length exceeds the others. This law, 
already mentioned above; (§9,) is seen no less in the body as a whole, and 
in the external form, than in the internal form, or the texture of its parts. 
The whole length of the body, much exceeds its breadth and thickness. 
It is divided into three principal regions, the head,trunk,a.nd the limbs,ox 
extremities. Of these, the head alone is round, but it is only the upper 
and bulging extremity of the vertebral column, that is of the osseous 
base of the trunk, hi which the dimension of length evidently predomi- 
nates. This column is enveloped by lateral expansions, producing ca- 
vities designed to lodge the apparatus placed before them, but it is not 
entirely concealed. The excess of length is most manifest in the ex- 
tremities,, generally, and in their different parts. It is the same with 
all the particular systems. The dimension of length much exceeds 
the other two in the vascular and nervous systems. It is especially 
marked in the hair. The number of the long bones, muscles, and 
fibrous organs, is much greater than of those which are broad or thick. 
The intestinal canal, the trachcea, ureters, urethra, &c, are very nar- 
row in proportion to their length. 

This rule applies exactly to the texture, since the fibrous is the most 
common of all, and every large fibre is divided into an endless multi- 
tude of others which gradually become smaller and smaller. 

§19. III. The structure of the organism is radiated. From the cen- 
tral parts, which are largest, originate others, which are smaller, which 
move in all directions, and in which the dimension of length especially 
predominates. Thus the extremities arise from the trunk : the long, 
and narrow ribs, from the spine ; the nerves, from the brain, spinal 
marrow, and ganglions, the vessels from the heart. But, besides these 
grand centres, from which the rays commence, there is an infinite 
number of the second order, since each ray usually divides into several, 

(1) Perhaps it would be better to suppress, not only the fibrocartilaginous system, 
which is a mixed, or compound tissue, as its name indicates, but also the sei i 
tern, which has the same relations with the mucous, or cellular tissue, as exists be- 
tween the dermoid and epidermoid, which Meckel has very properly united. * . 1 . 



32 GENERAL ANATOMY. 

which, in some systems, particularly the general, as that of the nerves 
and vessels, also, in their turn subdivide. The rays then ramify. 

Another general law is, that the number of rays augments as they 
depart from the principal centre of radiation, and their volume diminishes 
in the same proportion. Thus, instead of one long bone, as in the arm 
and thigh, we find two, which are smaller, in the forearm and leg r 
twenty-six in the foot and twenty-seven in the hand, still smaller. The 
number of the muscles and tendons inserted into the bones, and of the 
ligaments, multiplies in the same manner, and they diminish in size in 
the same ratio. In the whole course of the nervous and vascular trunks, 
branches and twigs are constantly sent off in every direction, at dif- 
ferent angles, and at certain distances from the principal trunks they 
divide into others still smaller, which are themselves again subdivided. 

This division is true, not only in respect ta length, and from with- 
out, inward : it also, occurs in the thickness of the organs ; for the mus- 
cles and nerves represent bundles composed of cords, which are, in their 
turn, formed of fibres and filaments. 

§ 20. IV. At the side of this law of ramification proceeds another, 
the law of anastomosis. These rays, it is true, subdivide a great many 
times, but the subordinate rays which result from this division, unite in 
different ways with each other, and with the principal ray. The same 
remark is true in regard to the continuity, that is, to the thickness of 
the organs ; for these anastomoses take place from above, downwards, 
and also from within, outwards. The different trunks, branches, and 
twigs of the nerves and vessels, the different tendons of the same mus- 
cle, the simple fibres, their fasciculi, both large and small, in the nerves, or 
at least in many muscles, the fibres of the bones, and those of the fibrous 
organs, mutually anastomose together. We can, to a certain extent, 
mention here those bones placed side by side, which, in addition to the 
ligaments necessary to keep them in place, are connected by interos- 
seous membranes. 

§ 21. V. These rays are not straight, hut usually more or less curved. 
This law, which has been termed the law of the spiral line, is seen in 
the vertebral column, which describes several curves ; it is confirmed 
also by most of the long bones. The cochlea, semicircular canals, 
several vessels, excretory ducts, and nerves, are also examples. Fi- 
nally, this is sometimes seen very evidently in the double monsters : 
since, when two heads are placed side by side, or two bodies are united 
by a head, the direction of these two bodies or two heads is always dif- 
ferent ; so that the monster, considered as a whole, appears spiral. 

§22. VI. The different organs are sometvhat analogous. (1) It has 
already been stated (§5) that the texture of the most dissimilar organs 
can be reduced to two elements of form, which are generally united • 
we have there indicated the analogy which exists between the final 
structure of the organs, and to which many writers have wrongly gj yen 
still more extent. As the structure of almost all the organs is radi- 
ated, (§19,) it follows that the analogy of their external form is demon- 

(1) See our Memoir on the analogy oj organic forms, iaour Beytraee zur ner 

glcichcndcn Anatomic, vol. ii. p. '„'. J 5 



GENERAL LAWS OF FORMATION. 33 

strated. It exists even where there is no manifest radiation ; since we 
there remark parts first dilated, and others which are contracted. 
Thus, the brain is joined to the spinal marrow, the vertebral column 
to the skull, the vascular trunks to the heart, the esophagus to the buc- 
cal cavity, the intestinal canal to the stomach, the trachea to the, 
larynx, the cystic duct to the gall-bladder, the ureter to the pelvis of 
the kidney, and the urethra to the bladder. 

Another great analogy between the different systems is established 
by the circumstance that those which vary the most from each other 
are formed after the same type in the same parts of the body. Thus, 
the simple trunk of the arteries of the superior or inferior extremities is 
almost always divided into two different branches, at the place where 
the number of bones is doubled ; in general, the divisions and unions 
correspond exactly in the different systems situated near each other. 
The number of the arteries destined for the fingers and toes is the same 
as that of these appendages. The nervous trunks and the vessels ana- 
stomose in the palms of the hands and soles of the feet. In the same 
manner, the tendons of the flexor and extensor muscles of the fingers 
and toes are united by mucous and tendinous slips. The different parts 
of the nervous system and of the vascular system proceed together. 

The whole form of the body is repeated not only in those systems 
which are generally diffused in the entire economy, and which form a 
whole more or less continuous — as the cellular tissue and the nervous, 
vascular, osseous, and muscular systems — but also in each of the 
organs. We should refer to this the form already pointed out as 
belonging to so many systems, the peculiarity of which is an enlarge- 
ment at one extremity and a continuation into a narrower process at the 
other. We must refer to this also the manner in which most of the 
organs, and principally the glands, receive their vessels. In fact, we 
always observe a considerable depression, a fissure, about the centre of 
these organs, through which the vessels enter and emerge exactly as 
in the fetus. Here the organ is open to a certain extent, and is much 
more so the nearer it is to its formation, exactly as in the fetus, which 
at first is open entirely before. 

The peculiar analogy of certain systems is still greater. This is 
seen particularly in the genital organs and the intestinal canal.(l) 

§ 23. VII. The body is formed symmetrically. We find an analogy, 
and even a resemblance to a certain extent, not only between the dif- 
ferent organs, but particularly also between their different regions. (2) 
This analogy may be demonstrated, both in the breadth, and in the 
length, and thickness, or even between its right and left sides, (3) be- 
tween its upper and lower extremities,(4) and between its anterior 

(1) A. A. Meckel. De genitalium et intestinorum analogia, Halle, 1810. Trans, 
in J. F. Meckel's Bcytr. zur vergl. Anat. vol. ii. p. 2. No. 1. 

(2) J. F. Meckel, loc. cit. p. 95. 

(3) Du Pui, De homine dcxtro et sinistro, Leyden, 1790.— Heiland, Darstellung 
der Verhceltniiscn zwischcn der rechten und linken Hodfle des menschlichen Kcer- 
pers, Nuremberg, 1807.— F.oschge, De sceleto hominis symmctrico.— Erlangen, 1795. 
—J. B. Monteg-gia, Fasciculi pathologici, Turin, 1793 : morbi symmetrici et asym- 
metrici.— Mchlis, De morbis hominis dextri et sinistri, Gcettino-en, 1818. 

(4) Vicq-D'Azyr, Sur les rapports qui sc trouvent entre les usages, et la structure 
Vol. I. 5 



34 GENERAL ANATOMY 

and posterior faces.(l) \\ e must here remark generally, that the 
similitude is never perfect, and that usually one extremity predomi- 
nates, more or less, over the other. This is sometimes expressed by 
the greater volume, and sometimes by the greater development in trie 
radiation of corresponding parts. Nor is the symmetry equally great 
in all directions, nor between the different corresponding regions. 1 he 
most perfect is the lateral symmetry, or that of the two sides oi the 
body ; and the most imperfect, that of its anterior and posterior laces. 
The nervous, osseous, ligamentous, and muscular systems, and the 
genital apparatus, are the most symmetrical parts ; we find less sym- 
metry in the vascular system and in the thoracic and pelvic viscera, if 
we except the genital apparatus. 

§ 24. 1. The most perfect lateral symmetry is in the external form, 
and on the surface of the body. Hence, it is better known there. In 
fact, the body seems to be composed of a right and a left half, since 
most of the organs are double, and those which are single, are placed 
more or less on the median line, so that a plane drawn from before 
backward, would divide them into two nearly equal parts, as they 
are formed of two lobes united and blended on the median line. 
These latter, when placed between cavities, form _ septa ; and on the 
contrary, are called media of communication, commissures, when placed 
between two corresponding parts, which are otherwise separated. 

Similar arrangements are found in all the systems, and we may say 
with justice that a commissure exists more or less perceptibly in all 
the body, although it is often interrupted ; this, at the same time, forms 
a septum between the right and left sides. (2) Thus, the falx cerebri 
descends from before backward, from the centre of the skull ; and the 
internal ridges of the frontal and occipital bones correspond to it. Be- 
low it, is the corpus callosum which unites the two hemispheres of the 
cerebrum; below, is the septum lucidum, formed of two layers 
closely applied to each other, and which represent in the brain what the 
falx and spinous ridges have in the skull. The nasal cavity is divided 
into two parts by a partition, which is bony above and behind, and 
cartilaginous before ; the former of these portions being formed by a part 
of the os ethmoides, and by a particular bone, the vomer. The frena 
of the lips in front, and the uvula behind, represent this septum in the 
mouth. In the chest, the internal parietes of the pleura, which partly 
touch, and are partly separated by organs placed between them, form 
the anterior and posterior mediastina, and thus establish a line of demar- 
kation between the two halves of the thoracic cavity. A longitudinal 
septum, generally perfect, exists between the right and left sides of the 
heart. This septum is only indicated in the abdomen, where the two 
halves seem blended together ; the division has been destroyed, or its 

des quatre cxtremites dans Vhommc et dans les quadrupedes ; in Mem. dc Paris- 
1774, vol. ii.— Meckel, loc. cit., p. 97— 148.— Falguerolles, De exlremitalum analo^ia 
Erlangen, 1780. ° ' 

(1) Meckel, loc.cit., p. 148. 

(2) F. L. H. Ardieu, Considerations sur la ligne medianc, Strasburg, 1812. 



GENERAL LAWS' OP FORMATION. 35 

formation has been prevented, by the considerable mass of organs 
which are inclosed by this cavity. We trace it, however, forward 
and above, in the suspensory ligament of the liver which extends from 
the inferior face- of this gland to the umbilicus, and below, in the analo- 
gous but less extensive fold of the peritonreum, which reaches from 
the bladder to the umbilicus, covering the remains of the obliterated 
umbilical artery and urachus ; and finally, behind, in the other fold of 
the peritonaeum, which goes from the anterior face of the lumbar ver- 
tebrae to the intestinal canal, and which is called the mesentery. On 
the median line of the penis in the male, and of the clitoris in the 
female, we find a perpendicular septum. The corpus spongiosum of 
the penis, and the septum and the raphe of the scrotum in the male, 
are situated exactly on the median line. The cellular tissue, which 
unites the skin to the subjacent parts, is thicker in all regions of the 
body on the anterior and superior, than on the posterior face. The ves- 
sels frequently anastomose together on the median line, as is seen in 
the coronary arteries of the lips, the sinuses of the medulla spinalis, 
and the cerebral arteries, which, supplying the two hemispheres of the 
brain, unite by numerous transverse branches. So, likewise, the two 
vertebral arteries unite on the median line, to produce the basilary, 
and the anterior and posterior spinal arteries descend along the spinal 
marrow. Several sinuses of the dura mater exist on the median line 
of the skull. The aorta, venae cavae, thoracic canal, the azygos vein, 
and partly even the esophagus, describe a curve, which corresponds 
very nearly to the median line of the thoracic and abdominal cavities. 

The vertebral column, sternum, occiput, os frontis, os elhmoides, and 
os sphenoides, are those parts which are unmated and distinct, and 
serve to join the corresponding parts of the same system, as they are 
united with them, and wedged in by them. Those bones which meet 
on the median line, but remain always distinct, although united by 
an intermediate substance, as the ossa parietalia and ossa iba, form the 
connecting link between them and those which do not touch in the 
least. 

The brain and spinal marrow, the heart, womb, vagina, prostate 
gland, bladder, urethra, thyroid, and thymous glands, the intestinal 
canal, the trachea, larynx, and tongue, are unmated, but are formed 
of two similar portions, between which the median line passes, at least 
to a certain extent. 

All the other organs are mated, and are rarely united by their own 
proper substanee. They are connected in various ways. Thus ihe kid- 
neys be on each side, and are united above by the blood-vessels, and be- 
low by the ureters, which go to the bladder. The lungs are joined above 
both by the trachea and pulmonary blood-vessels, while the extremi- 
ties are perfectly insulated, or at least are united only at their upper 
ends, where but a small number of parts are found belonging to them 
in common.(l) 

(1) See a note by J. F. Meckel, on the differences between the rig-ht and left por- 
tions of the body, in respect to the proportional size of the arteries and veins, in 
Deutsches Arrhir. fi'ir die Physiologic, vol. i. p. 450. 



36 GENERAL ANATOMY 

§ 25. 2. The symmetry of the upper and lower parts of the body is 
less than than that of the lateral portions ; but it cannot be mistaken. 
It is especially seen in the pectoral and abdominal members where it 
is indicated by the number of subdivisions which they include. 1 ne 
form and number of the parts of the different systems, which contn-- 
bute to form the members, are the same in all, except some slight dif- 
ferences, which depend for the most part upon the difference of func- 
tions performed by the superior and lower extremities, so that one can- 
not doubt but that these are constructed after the same type, even in 
man. The upper and lower regions of the central parts of the whole 
body also correspond, when the head and trunk are supposed to be 
united. To the central part of the vertebral column alone are attached 
peculiar and distinct bones, called ribs. Next come, above and below, 
vertebrae without ribs ; above are the cervical, below the lumbar, the num- 
ber of each being less than that of the dorsal. To the former is annexed 
the head, to the latter the sacrum, which is, like the head, an aggre- 
gation of large vertebras ; these are similar to each other, partly in 
their increase of size, and also because they unite more slowly, and 
sometimes do not fuse upon the median line, because the number of 
pieces of which each is composed has become more considerable, be- 
cause they are more solidly united to each other ; and finally, because 
they are fused together, and articulate with moveable bones — the coc- 
cyx below, the lower jaw above. Hence, we may consider them as 
imperfect vertebra, since the first represents the arch, the second the 
body of the vertebra. 

The upper and lower parts of the body correspond manifestly also 
in the energy with which hair is there produced. We may espe- 
cially compare together the hairs of the beard, of the nose, and genital 
parts, which surround the upper and lower openings of the intestinal 
canal, and the apparatus connected with it, since they appear in the 
game places, and are or are not developed under the influence of the 
same conditions. 

But the two extremities of the intestinal canal, and the organs 
which are there annexed,- also correspond. 

The intestinal canal commences above by a considerable dilatation, 
the buccal cavity and the pharynx ; next comes the esophagus, the 
muscular parietes of which are attached to the adjacent bones, and 
are susceptible of voluntary motion. The same arrangement is ob- 
served in its inferior extremity, the rectum, which continues above with 
the colon. The parietes of those two extremities also are provided 
with very strong muscular fibres. The same thing occurs a second 
time in the remainder of the alimentary canal, and two new ex- 
pansions are remarked ; the superior is the stomach, which is continued 
with the small intestine ; the inferior, the colon, and still farther the 
ccecum, which opens in the same manner with the large intestine! 

Farther, in the upper and lower parts of the body there are several 
organs which manifestly correspond. The respiratory apparatus may 



GENERAL LAWS OF FORMATION. 37 

be compared with the urinary apparatus ; and the thyroid and thymous 
glands, the tongue, and the nose, correspond to the genital parts. 

The first comparison is established more easily than the second. 
The principal organs of the two apparatus, the lungs and the kid- 
neys, are similar : first, in number, they are two : second, in situation, 
they are separated one from the other — are not inclosed in a com- 
mon sac, and are placed along the vertebral column : third, in their 
mode of connection ; for they are united, by large vessels which enter 
them, and canals which come from them, all of which are united on 
the median line, the lungs by the trachea, and the kidneys by the ure- 
ters and urethra : fourth, by their structure ; apart from the general 
conditions presented by the texture of the glandular organs, the 
formation of the cellules of the lungs is represented by the size of the 
vessels which secrete the urine, and of the large or small cellules so 
commonly found in the kidneys. 

The genital parts and the other organs maybe compared, and a paral- 
lel drawn between them from structure and functions. The thymous 
gland, which is composed of two lateral lobes more or less avidently 
separate, corresponds to the ovaries and testicles in its glandular struc- 
ture, and in its situation, since it is the deepest of all. The thyroid 
gland, an unmated^ organ, is placed much higher and more externally, 
and represents the prostate gland with the vesiculee seminales, and 
the uterus. The external and internal form of the tongue, the abun- 
dance of its vessels and nerves, the development of these vessels and 
of these nerves in papillae, the nature of its epidermis and, finally, the 
arrangement of its muscles, vessels, and nerves, resembles the glans 
penis, and clitoris. So, too, with the nose and larynx ; the first may 
be compared with the urethra and vagina, in regard to its structure, its 
texture, and its functions. With regard to the larynx, the powerful 
influence of the state of the genital parts upon the bosom and on the 
voice, already assures us that we may compare it to these organs, but 
as it fulfills peculiar functions, we ought not to expect to find in the 
lower half of the body any thing exactly corresponding to it. 

Besides the analogies already indicated between the upper and lower 
halves of the body, they correspond : a. in the arrangement of the vascu- 
lar system. The aorta and venae cava? are distributed in almost the 
same manner, and form, above, the vessels of the head and upper ex- 
tremities, and below, those of the pelvis and lower extremities. 

b. In the arrangement of the nervous system : the cerebral nerves, 
and even one of the spinal nerves proceed from* behind, forward, while 
the direction of those of the spinal cord, except the upper, which move 
somewhat obliquely, is from before, backward. The spinal marrow, 
after giving off the spinal nerves, is prolonged, and sometimes bulges 
like a button, which corresponds to the brain. 

c. In the arrangement of the muscular system : since several of the 
muscles of the back and belly are repeated in the upper and lower 
parts of the body. 



38 GENERAL ANATO&n 

We have already remarked that the greatest analogy exists in the 
arrangement of all the systems which unite to form the extremities. 

The diaphragm forms between the upper and lower parts ol the 
body a partition resembling the median line. (§ 24.) 

§ 26. 3. The more obscure analogy between the anterior and jioste- 
rior faces of the body is generally neglected for that which is seen in 
the two directions above mentioned. However, we must point it out, 
although the external face of the body offers but few faint traces of it. 

The vertebral column is evidently represented on the anterior face of 
the body by the sternum, since this bone closes the cavity of the chest 
before as the vertebral column closes it behind. The sternum corres- 
ponds particularly to the centre or pectoral portion of the vertebral co- 
lumn ; nevertheless, it extends both above and below, beyond the car- 
tilages of the ribs with which it is united, and as it is shorter than the 
pectoral portion of the spine, so that, in regard to one dimension, it re- 
presents only an imperfect spine, the upper and lower extremities, 
which do not support any ribs, are incomplete imitations of the cervical 
portion and of the lumbar portion of this column.- 

The costal cartilages represent also the false ribs, since they remain 
always behind the true ribs, either in their smaller size or in their tex- 
ture and chemical composition. 

In the anterior part of the abdomen there are no bones to correspond 
to the vertebral column ; but the linea alba, that strong tendinous cord 
which extends along the median line from the sternum to the pubes, 
certainly represents it. 

The internal mammary and epigastric vessels on the anterior face 
of the .trunk, correspond to the large vascular trunks which descend 
along the vertebral column ; and the medulla which passes through 
the spine, resembles the grand sympathetic nerve situated before this 
column. This law is recognized also in the doubleness of each lateral 
half of the spinal marrow which is itself composed of an anterior and a 
posterior cord, in the existence of an anteriorand posterior series of roots of 
the spinal nerves, and in the division of the encephalon into the cerebrum 
and cerebellum. In the same manner the frontal and occipital bones cor- 
respond before and behind. In the spine, the arched ribs before, 
resemble the vertebral arches behind, and the more so, as the latter are 
developed by separate points of ossification. 

The analogy extends also both to the trunk and limbs, between the 
extensor and flexor muscles, in respect to number, size, form, situation, 
and mode of insertion. * 

§ 27. We have said above (§ 23) that the symmetry is not per- 
fectly regular. We have explained the possibility of this fact, and its 
reality is already in part proved by the details into which we have en- 
tered. A glance at the different systems, and at the different regions, 
will prove that the differences we have mentioned really exist. The os- 
seous and ligamentous system, as also that of the voluntary muscles 
and the nerves associated with them, appear to be essentially formed 
of two exact halves, which correspond so closely, in volume form and 



GENERAL LAWS OE FORMATION. 39 

situation, that they are almost perfectly similar. On the contrary, the 
vascular system, the grand sympathetic nerve, the organs of respira- 
tion, of digestion, and of the urine, are not symmetrical. The heart is 
not placed perpendicularly but obliquely, so that its septum does not cor- 
respond to the axis of the body. In its two portions we see the same 
divisions and the same general arrangement ; but they differ much in 
capacity, and in the thickness of their parietes. The vascular trunks 
which belong to these two parts correspond neither in external nor in- 
ternal form, nor in destination. The vascular system, considered as a 
whole, is composed of four trees united by the heart : these are the ar- 
teries and veins of the body, and the arteries and veins of the lungs. 
The first two trunks, as well as the last two, accompany each other, 
but neither the two parts of each tree, nor the portions of different trees 
which proceed together, perfectly resemble each other. The trunk of 
the aorta is not placed exactly on the median line, but is found, first on 
the right, and then on the left of the vertebral column. Hence it is 
arched. From this arch the carotid and subclavian arteries arise by 
a common trunk on the right side, while they have separate origins on 
the left. The large vessels of the right and left sides are very seldom 
alike in their origins, volume, and rout. The two venae cavse incline 
to the right ; on the same side we find between them the azygos vein 
to which the small vein of the same name corresponds, but imperfectly 
on the left side. The two arteries of the heart arise each by a single 
trunk from their respective ventricles ; but the pulmonary veins, when 
they arive at their auricle, are four in number, while those of the body 
are only two. So, likewise, we almost always see three or four veins 
corresponding to a single secondary arterial trunk. 

The two lungs have neither the same volume nor the same form : 
the right lung is larger than the left, and is composed of three lobes ; 
and its bronchia is shorter, but broader. For this reason, and also on 
account of the obliquity of the heart, the anterior mediastinum is di- 
rected obliquely from above downward, and from right to left. 

If we extend our observations to the digestive system, we see the 
esophagus inclines more to the left than to the r right, and that the sto- 
mach occupies the left side, whence it extends obliquely to the right, 
and near its left portion is the spleen, which, even when connected 
with the pancreas also situated more to the left than the right, cor- 
responds but slightly to the liver, which, with its voluminous mass, fills 
all the upper parts of the right portion of the abdomen. The mesentery 
extends from above downwards, and from right to left. The large in- 
testine continues with the small intestine, not on the median line, but 
on the right side ; its right and left halves do not correspond. The kid- 
ney and capsula renalis of the right side are situated lower than those 
of the left, and have not exactly the same form : their blood-vessels and 
their excretory ducts are rarely arranged in a similar manner. The 
genital organs are more symmetrical ; nevertheless, one testicle is 
sometimes larger than the other, and sometimes one remains in the 
abdomen, when the other descends into the scrotum. The direc- 



40 GENERAL ANATOMY. 

lion of the womb is often oblique, which does not arise from accidental 
circumstances. 

The least symmetrical organs correspond, however, in this respect, 
that they are formed at least of two similar halves. The digestive ap- 
paratus presents so little symmetry only because this want of symme- 
try is necessary from its length, and the functions it executes. Its 
whole extent may be divided into two nearly similar parts, which, 
setting aside its cylindrical form, are well indicated by the arrangement 
of the vessels. In fact, in almost its whole length, that portion of its 
circumference which is turned towards the mesentery, and in some 
parts especially, as the stomach, two opposite portions of the same cir- 
cumference receive vessels which ramify uniformly, and which, pro- 
ceeding each upon one of the portions of this canal, anasiomose oppo 
site their point of commencement. 

Hence why the lateral parts of the least symmetrical organs resem- 
ble each other so much that the lateral symmetry is more perfect than 
the others, and the parts which correspond laterally execute precisely 
the same functions. Hence especially this more distinct symmetry, 
which in several respects, is indicated in other directions so obscurely 
that it is not perceived by one unaccustomed to tracing analogies, and 
who knows not how important it is to determine them when we wish 
to explain the cause of the phenomena of formation. 

But the want of perfect symmetry may usually be explained by the 
law above mentioned, (§ 23,) and, in accordance with which, one of two 
opposite corresponding parts is almost always more developed than the 
other. All the right side is larger than the left. The right portion of 
even the most symmetrical organs is larger than the left. The larger 
lung and the kver are placed on this side. The common trunk of the 
right carotid and subclavian arteries seems to be produced by a greater 
energy of the formative power. The cerebrum develops itself at the 
expense of the cerebellum, and the inferior part of the spinal marrow 
offers hardly a trace of expansion which may be regarded as corres- 
ponding to the brain. Where such marked differences exist, we see 
another organ very largely developed in the parts where the system 
is so considerably diminished, of which there is scarcely a trace on the 
opposite side. The spinal marrow terminates rather high in the 
vertebral column, although we see appear in the pelvis, and in front of 
the sacrum which corresponds to the cranium, (§ 25,) a special appa- 
ratus, that of the genital system, which very much resembles the nerv- 
ous system in structure and functions. 

On the contrary, on the opposite side, at the upper extremity of the 
body, where the brain so remarkably predominates, the generative sys- 
tem is but imperfectly indicated ; for, first, the different parts here situ- 
ated are not united in a single body, as constantly happens when 
the development of parts, which, if regularly formed, constitute a 
whole, is disturbed and cannot be perfected ; secondly, these different 
parts have not a common function, since the tongue belongs to the di- 



GENERAL LAWS OF FORMATION. 41 

gestive, and the nose to the respiratory system, while the thyroid and 
the thymus glands are not included in any. 

The differences between the organs which are here compared are 
such as to oblige us to enter upon a more profound examination, in 
order to prove that the analogy established is not forced. We have 
said that the genital system corresponds, partially at least, with the 
brain, or, perhaps more exactly, with the nervous system. 

Our arguments are : 

1st. This proposition is rendered very probable by the functions of 
the two apparatuses. The nervous system is the principle of all life 
and of all formation in the organism. The existence of the individual 
is more closely connected with the integrity of its central parts than 
with that of any other organ. A similar relation exists between the 
principal parts of the generative system and the life of the species. We 
may even, and with justice, say that the generative system has the 
same effect on the formation of the individual, when we reflect upon 
the remarkable modifications its presence or absence produces in the 
activity of the mind and of the body. 

2d. The form of these two systems argues in favor of this opinion. 
The remarkable exception made, by the perfect symmetry of the geni- 
tal organs, to the common arrangement of the other organs with which 
they have some affinity, must be mentioned. The round form of the 
ovaries and testicles also furnishes a point of comparison. The texture 
of the testicles and brain is very analogous, since both are formed of 
very delicate fibres, similar in flavor and chemical composition. The 
dura mater forms septa between the two hemispheres of the brain, 
and between the cerebrum and the cerebellum, which partially resemble 
the septum of the scrotum, and partly those found in the substance 
of the testicle, which are formed by the prolongation of the tunica 
albuginea. The corpus highmorianum, which arises from the testicle 
by numerous roots, may be compared to the spinal marrow ; it opens 
externally on each side by an excretory canal comparable to the 
nerves, although the brain and spinal marrow are necessarily con- 
nected with the organs by several rays. But few lymphatics arise 
from the brain and the spinal marrow, while very many originate in 
the testicles, in order to strengthen the influence which those organs 
have on the body. We ought also to remark that the arrangement of 
the blood-vessels in the brain and testicles is very analogous, since in 
both the circulation of the blood is evidently retarded. 

3d. The study of these organs comparatively in the animal series 
presents still more points of agreement, of which we shall mention only 
one of the principal, the development of one of the two systems accom- 
panied by the wasting of the other. 

We have already stated (§ 25) several arguments which justify the 
comparison established between the genital parts and those organs situa- 
ted in the upper half of the body, the development of which appears to be 
restrained in part by the brain, as that of the lower extremity of the 
spinal marrow is checked by the genital system. It might be objected 

Vol. I. 6 



42 GENERAL ANATOMY. 

that the uses of the tongue relate to the functions of the alimentary 
canal, and so with the nose, which is very intimately connected will 
the organs of respiration. But on one side, the genital system is on y 
developed out of the alimentary canal ; and again, the senses oi smell- 
ing and of taste are at least as closely connected with the sexual appe- 
tite as with that for food. We shall avail ourselves of this favorable 
opportunity to explain the difference between the upper 'and lower 
extremities of the body, relatively to the arrangement of the two extre- 
mities of the alimentary canal and of the organs near them. Below, 
the canal is entirely separated from the genital and urinary systems 
blended together ; above, on the contrary, it unites with the respiratory 
system, and the tongue inclosed in the buccal cavity corresponds to a 
part of the genital apparatus. This arrangement depends partly on 
the analogy between the genital and digestive systems, and partly on 
the fact that the epiglottis and velum palati form septa, which, by 
changes in their direction, can separate the nasal cavity and the trachea, 
and consequently the organs of respiration, from the buccal cavity, 
and even from the pharynx, and necessarily from all the digestive ap- 
paratus. 

The form, situation, texture, and liability to the same kind of disor- 
ganization, justify the comparison established between the trryroid 
gland and the womb, or prostate gland. That the thymus gland 
corresponds to the testicles and ovaries, is known from its similarity 
in form, situation, texture, the analogy of the fluid secreted, and the cir- 
cumstance tltat its activity ceases when the testicles or ovaries come to 
maturity. 

The differences between the anterior and posterior faces of the body, 
which we have compared together, are reconciled in the same manner. 
All the posterior or dorsal half is more completely developed and more 
strongly marked than the anterior. The occipital is thicker than the 
frontal bone, and the bones of the skull are generally stronger than 
those of the face. The face is naked, while the skull, especially be- 
hind, is thickly covered with hair. The muscles are more numerous 
and stronger along the spine than along the sternum. The sternum 
is formed like an imperfect spinal column ; as it represents only the 
anterior part the bodies of the vertebra properly speaking, and corres- 
ponds to the lower extremity of the spine, to the coccyx. The linea 
alba is still more imperfect and feeble. The ribs ossify ; the costal 
cartilages do not ossify, or but rarely, and at an advanced age. The 
posterior part of the ribs is, in its turn, much stronger than the ante- 
rior. The ribs below the tenth belong properly to the spine. An 
artery winds on each side along the rudiment of the anterior vertebral 
column, and corresponds to the aorta, which is placed before the proper 
spine ; the whole in conformity to the law, that formations of an infe- 
rior order are characterized by a want of concentration.(l) 

(1) Sec our remarks on the progressive advancement of the organization or on the 
difference between the formations of a superior and inferior order, in our lie>itrwsc 
zur vcrglcichendcn Anatomic, vol. ii. part 1, Leipsick, 1811. ° 



GENERAL LAWS OF FORMATION. 43 

Notwithstanding these adjustments, corresponding parts, even the 
right and left halves of the body, always differ essentially. The sym- 
metry is, then, not perfect. The organization of man has no advan- 
tage in this respect over that of animals, notwithstanding what Hei- 
land intimates when he says that the dualism (lateral) is particularly 
marked in the human body.(l) So far is this from being true, that 
the farther we proceed from man, the more distinct is the lateral sym- 
metry, with a few exceptions. For not only do the organs, which are 
but slightly symmetrical in him — for instance, the heart, some parts 
of the vascular system, the respiratory system, the urinary system, 
and digestive system — become more and more so as we descend the 
scale, but even the organs most symmetrical in man, as the nervous 
system, and the brain especially, become still more so in animals. 

§ 28. The conditions enumerated form the object of an anatomy, 
which compares a body with itself, considering it only in reference to 
its different parts. But this body may be compared with itself, consi- 
dering it in time, that is to say, in regard to the different periods of its 
existence. 

• VIII. No organ possesses precisely the same qualities at all periods 
of the existence of the organism. There are none which are alike at 
all periods of their existence. Each organ, and consequently the 
whole organism, passes through certain regular and normal stages. (2) 
This very important law, called the law of development, gives rise to 
the following considerations : 

1 . There is for each organ, and for the whole organism, a period of 
imperfection, in which the whole development is not attained ; this is 
called the period of youth, or infancy ; a second called that of mature 
age, or period of maturity, of perfection ; and a third, that of old age, 
or of decline. 

2. The resemblance is much greater between different organs, and the 
different regions of the body, the nearer each respective organ, and the 
whole organism, is to its origin ; the more recent the organism, the 
more symmetrical^ it is. The heart is, at first, perpendicular ; its 
septum corresp*oiKls exactly to the median line, and its two portions 
have the same size and thickness. The liver projects as much to the 
left side as to the right ; its left lobe is as large as the right, and its sus- 

(1) Loc. cit. p. 5. Walther (Physiologic, vol. ii. p. 102.) is not more correct when 
stating' that the dualism of the two portions of the body is less evident in the inferior 
classes of the animal kingdom, and commences to be perceptible only when the 
nervous and muscular fibres can be distinguished. In fact, the bodies of many ani- 
mals destitute both of muscles and nerves are evidently formed of two symmetrical 
halves. 

(2) See, in regard to the changes which supervene during the first periods of ex- 
istence till birth, the work of F. G. Danz, Grundriss der Zergliederungskunde des 
ungebornen Kindes, Francfort and Giessen, 1792-3 ; and for the particulars of the 
structure of the body till the latter periods of life, the dissertation of Seiler, {Anatomies 
corporis humani senilis specimen, Erlangen, 1800.) Consult also Hopfengcertner, 
Einige Bemerkungen ubcr die menschlichcn Entwickelungen, und die mit derselben 
in Verbindimg slchendcn Krankhciten, Stuttgard, 1792. — A. Henke, Ucber Entwick- 
climgenuiidEntwickelungs-KrankfieitendesmenschlichenOrganismus,'Nuremberg ) 
1814. — C. A. Philites, Dc clccrcmento altera hominum cetatis pcriodo, seu dc marasme 
scnili in specie, Halle, 1808. 



44 GENERAL ANATOMY. 

pcnsory ligament is on the median line. The stomach is perpen- 
dicular. The upper extremities arc more similar to the lower than at 
later periods. The sternum is, at first, composed of several cartilagi- 
nous pieces, which afterwards become so many bones. Each piece is 
placed between two costal cartilages, and the latter are always implanted 
in a groove, hollowed from two pieces of bone. This analogy after- 
wards disappears, since the osseous pieces, each of which corresponds 
to a vertebra, fuse together, so as to form only one body. 

Generally, the mode of development of the organs is the same, or at 
least almost similar, which increases the analogy remarked between 
different parts and different regions, during the first periods of life. 
Thus the spinal marrow, and probably also the brain, arise at first by 
two layers, which are not even united. The intestinal canal forms in 
the same manner. 

The heart is at first only a single cavity, with thin parietes. The 
cerebrum also exists before the cerebellum, and its parietes are ex- 
tremely thin in proportion to its cavity. The intestinal canal is a continu- 
ation of the umbilical vesicle or of the vitelline sac, as the genital and 
urinary systems are probably of the allantoid membrane. The ex* 
tremities of the urinary, genital, and digestive apparatus, are at first 
blended together, and form a drain. This arrangement certainly exists 
in the upper end of the body, for at first the palate does not exist be- 
tween the nose and the mouth, which form but one cavity. The male 
and female genital organs are more similar in form and situation when 
studied in the young fetus. 

3. The color of the organs develops itself gradually. At first, 
the whole body is whitish, and even transparent ; it gradually assumes 
a deeper color, and becomes opaque. Each organ does not acquire 
its peculiar color till a later period. 

4th. Every organ is softer and more fluid, the nearer it is to its 
origin ; it gradually acquires its normal degree of consistence, and 
its cohesion increases till the end of life. Thus, softness characterizes 
the first, and rigidity the latter periods of life. This law is founded on 
the fact that all the solids come from the fluids, both*at the period of 
the first formation of the new organism, and during the rest of life. 
The substance of the organ is not only soft and fluid, but it is also sur- 
rounded with an abundant fluid, or if hollow, it contains a liquid, the 
quantity of which is very considerable in proportion to the thickness of 
its parietes. The nervous and vascular systems prove this assertion. 
The vascular system is composed at first only of channels formed in 
a homogeneous material, and has no distinct parietes. The progres- 
sive increase in the consistence of the organs is clearly seen in certain 
portions of the vascular system, in the uterus, in the serous membranes, 
in certain organs, as the spleen and some fibrous organs, where an 
osseous tissue is formed, which is almost regularly developed in them 
at an advanced age. When the degree of cohesion equals that of the 
bones, there appears in the mass, at first homogeneous and fluid a 
peculiar system, very dense in relation to the others : this is the carti- 



GENERAL LAWS OF FORMATION. 45 

laginous, which gradually changes to a tissue still more solid, the 
osseous. 

5th. This state of great fluidity is attended with a want of a deter- 
mined texture during the first periods of existence. At first we do not 
see even globules in the organic substance ; these globules then ap- 
pear, but they are not yet united to form distinct organs ; when this is 
commenced, fibres are not yet formed. All these circumstances unite 
to strengthen the resemblance between different organs in the extreme 
periods of life. 

6th. All the organs do not appear at the same time. This proposition 
is true in regard to the whole system and to each of its different parts. 
It is more difficult to determine the order in which the systems are 
developed in man, and in the superior animals generally, which pass 
very rapidly through the first periods of existence, than in the inferior 
animals ; and it often happens that organs of great importance do not 
appear until the growth is terminated : but we are certain that vessels 
and nerves are the parts first seen in the primitive homogeneous mass, 
and that the intestinal canal begins to form almost at the same time. 
At first, the trunk of the body exists alone ; no trace of the limbs 01 
head is perceived ; next we see the head, then the upper extremities, 
and afterwards the lower, the parts of which also gradually develop 
themselves. The organs of sense and of generation are seen" at a 
period still more advanced. The muscles and the bones, especially 
the teeth, are developed still later. Finally, the dermoid system is the 
last to form, since a long period elapses during which the nails and hairs, 
the latter especially in certain parts of the body, are entirely wanting, 
or are developed but imperfectly. Naturally the similar parts 
are the slowest to show themselves in the regions which appear the 
last. 

7th. Tliese parts, which are but repetitions of other more perfect 
parts, and which especially correspond to them, are the last to appear. 
Thus the sternum and linea alba, do not appear till long after the ver- 
tebral column ; the thymus and thyroid glands are formed after the 
genital organs ; the right ventricle of the heart appears after the left. 

8th. The external form develops itself much more rapidly than the 
texture and chemical composition of the organs. There is no percep- 
tible difference between the gray and the white substance, in most of 
the cerebral mass, when its parts are entirely formed. A bone, when 
cartilaginous, has its external characteristic form. But this form dif- 
fers remarkably at different periods. 

Generally, the form is more simple, as the organ is younger. The 
brain has no circumvolutions nor layers ; and the cartilage forms a ho- 
mogeneous mass, although the bone is fibrous, and has not the same 
texture in all its parts. The heart, which afterwards contains cavities, 
is at first, single, and is formed like a vessel, &c. 

9th. The organs arise almost entirely by separate parts, which 
gradually unite to form a whole. The whole body, the nervous sys- 
tem, the intestinal canal, are, at first, formed of two halves, which after- 



46 GENERAL ANATOMY. 

wards unite upon the median line. The vascular system, at first, forms 
islands rilled with a fluid substance, isolated lakes, which, by slow de- 
grees, form themselves by intermediate passages into a canal, with nu- 
merous ramifications in theii intervals, and gradually give rise to a net- 
work of vessels. The kidneys are, at first, composed of several lobes, 
which are then more numerous than at subsequent periods. The bones 
develop themselves by several different points of ossification, which 
are afterwards united. 

10th. All the organs have not the same proportional volume at every 
epoch of life. The brain, the whole nervous system, the heart, the whole 
vascular system, the liver, the kidneys, and still more the capsulae re- 
nales, the thymus, and thyroid glands, are, at first, larger in propor- 
tion to the other organs, than they are at later periods. 

On the contrary, other organs, the intestinal canal, the spleen, the 
genital parts, and the lungs, remain for a long time relatively small. 
We also observe certain organs shrink after a time, before others, which, 
though small at first, had acquired considerable size. This is the case 
with the thymus gland, which is formed late, and the sexual organs, 
particularly those of the female. 

Hence the respective proportions of parts of the entire system differ 
very much at different periods of life. The clavicle, so small in the 
adult, is, at first, six times as large as the humerus and femur. 

In virtue of the same law, the mutual relations of different parts of 
the body do not remain the same at different periods of fife. The 
head, which at first does not exist, soon acquires almost the size of 
the trunk ; and the limbs are, for a long time, but stumps, the upper 
being the larger. 

11th. The duration of the organs is not the same. For this reason, 
the organism is not constantly formed of the same number of organs. 
Some of its parts are temporary, others remain during fife. The 
membrana pupillaris is destroyed before birth ; the membranes of the 
ovum, the placenta, and umbilical cord, disappear soon after this period. 
After a time those portions of the vascular system which coexisted 
with these organs, are entirely obliterated. A little later the thymus 
gland becomes smaller, and gradually vanishes ; at twelve years of 
age we cannot trace it. The first twenty teeth are shed at the age of 
seven years. 

The capsulee renales sometimes disappear in old age; and per- 
haps, the same thing occurs with the ovaries. 

We may establish it as a principle, that the parts which grow the 
latest, are those which disappear, or at least those which cease to be 
active the soonest, and which are most easily destroyed. This is 
proved by the facility with which cicatrices of the skin and of the 
bones open again in general diseases. 

Many of the organs which disappear are replaced by new organs 
As others serve only to replace those which are not sufficiently active' 
their disappearance is not necessarily attended with the formation of 



GENERAL LAWS OP FORMATION. 47 

new parts, and only with an increased action on the part of some 
already formed. 

12th. Some systems pass through a greater variety of degrees than 
others, not only in respect to texture, but in external form, situation, and 
proportional volume: the history of their life is more complicated. 
The vascular system stands first in this respect ; the intestinal canal, 
with its appendages the genital organs, come next. The osseous 
system, at different periods of life, varies very much. The differences 
are less in the nervous system, and still less in the others. - 

13th. In some parts we can always trace the primitive formation ; 
in others we cannot, although we Mnow not exactly the cause of this 
difference. Thus, in the adult, we rarely see the four pieces of bone 
of which the os occipitis is composed, or the two halves which unite to 
form the frontal bone, or the lower jaw, while the existence of the in- 
termaxillary bone, and the articulation of the mastoid portion of the 
temporal bone with its squamous and petrous portions, are always very 
perceptible. Nevertheless, this circumstance may possibly depend on the 
fourteenth law, and the fact, that the traces of the transitory normal 
formations, which correspond to the constant formations generally ex- 
isting in the animal kingdom, are preserved longer than those of any 
others. 

14. The degrees of development through which man jwsses from 
birth to the period of perfect maturity, correspond to constant formations 
in the animal kingdom.(l) All the organs prove this assertion. 

The fetus, in fact, is allied to animals much lower in the scale, (2) 
from the circumstances of the greater resemblance between the different 
parts and the different regions during the early periods of life, the 
smaller number, the uniformity of color, the greater degree of softness, 
the less distinct texture, the relative difference of volume of the organs, 
and their production by the union of parts at first isolated. The most 
general law in this respect is that the organisms which the fetus resem- 
bles, are the more inferior, the nearer it is to its origin when the com- 
parison is made ; whence it follows, that the embryo, from its first for- 
mation to the time of its maturity, passes through a series of forms more 
and more complicated. 

(1) See our Essay on the resemblances which exist between the fetal state of the su- 
perior and the permanent state of the inferior animals, in our Bcytragc zur vcrglei- 
chenden Anatomic, vol. ii. p. 11., No. 1., Leipsick, 1811; 

(2) There is, perhaps, in anatomy no axiom more incontestable than this; but we must 
guard against abusing it, and should not confound analogy with identity. Thus, it 
is too much to say that man, from the period of formation to that of birth, passes suc- 
cessively through different forms, which are permanent in the inferior animals. 
First, this proposition is never true in respect to all parts, but only in regard to some, 
so that the relations supposed by modern physiologists to exist between the human 
fetus and reptiles, fishes, ca:taceffi, &c, rest only on analogies, more or less remote, 
between some of its organs and those of the animals in these classes. Again, we 
must not forget that the human fetus, from the period of its formation, irresistibly 
tends to assume the peculiar form of man, and so too with those of all animals. 
These remarks seemed necessary to anticipate the forced applications which might 
be made of one of the discoveries most honorable to modern anatomy, and to keep 
within reasonable bounrls that enthusiasm which exists with us ; for by falsifying the 
principles of a science we retard its progress. F. T. 



48 GENERAL ANATOMY. 

The proofs drawn particularly from the organs are : 

a. In regard to the vascular system. At first only one system of 
vessels is found in the embryo, the omphalomesenteric vein, lhis state 
of the vascular system corresponds to what is observed in the medusae 
and zoophytes allied to them, in which also only one order of vessels 
exists : and farther, because the vessels have no proper panetes distinct 
from the mass of the body. When the development is more advanced, 
the heart appears as an enlarged point slightly dilated, a little muscu- 
lar, oblongs channeled, and curved from the vascular system, as in 
many worms, where, although a complex system of vessels exists, the 
heart is wanting. Even in the arachnides and the branchiopedous 
Crustacea, the heart resembles a thin elongated sac, and the vessels 
arise from its extremities and parietes. At first only one dilatation 
exists, even as in the most perfect Crustacea, where the heart is con- 
tracted to a sort of small quadrangular and muscular cavity. 

A later formation, in which a second dilatation is produced by the 
separation of the auricles with the venae cavee, corresponds to the heart 
of most mollusca, of fishes, and of the lowest reptiles ; this is more per- 
fect, and presents two cavities, each composed of an auricle and ven- 
tricle ; but here the two auricles and the two ventricles communicate, 
as the septum between them is imperfect. This formation includes also 
the hearts of certain reptiles, for example, that of the scorpion turtle, 
and of the lacerta apoda, and as respects the communication between the 
two ventricles only, that of most reptiles, of those which constitute the 
upper orders. At first, as only one ventricle exists, there is only one 
artery, which, as in the mollusca, fishes, and reptiles, commonly arises 
by a considerable muscular dilatation which is, in fact, a third cavity. 
The pulmonary artery does not begin to form a distinct trunk till after 
the aorta, and during all fetal existence these two vessels are united in 
a common trunk by the arterial canal. 

So too in most reptiles, particularly those where the heart is com- 
pletely xleveloped, we not only recognize two aortas coming from 
the heart, which meet at an acute angle, and are blended together ; but 
the pulmonary artery communicates during life with the corresponding 
aorta by a broad canal, as is evident at least in the turtle. In the 
plungers, among the mammalia, the communication between the two 
auricles is so often found open, that it forms a new analogy between 
the human embryo and animals. A peculiar system, that of the vena 
porta, which is intermediate between the arterial and venous system, is 
seen only in the vertebral animals : as we descend the scale, the veins 
of the intestinal canal empty immediately into the vena cava inferior. 
This system of the vena cava is deficient during the first periods of 
fetal life, and the blood of the intestinal canal then returns directly to 
the heart ; since the vena porta is the first vessel which appears, and 
the liver is not yet formed. We trace this primitive formation in the 
venous duct, even when the development is perfect. 

b. The nervous system also somewhat resembles the organization of 
animals. 



GENERAL LAWS OF FORMATION. 49 

a. It is formed by the union of two distinct cords, and is similar in 
tins respect to the arrangement in most invertebral animals, in which 
the two cords which unite one ganglion to the following are more or 
less evidently separated from each other. 

/3. As at first the spinal marrow exists alone, there also the forma- 
tion corresponds to that of the most inferior worms. 

7. The spinal marrow is much longer at first, and descends lower in 
the vertebral canal ; even so the medulla dorsalis of worms, of most 
mollusca, of fishes, of several reptiles, and of all birds, extends to the 
posterior extremity of the body ; and even in almost all the mammalia 
it is longer than in man. In the fetus, a cavity extends entirely through 
it : in the superior vertebral animals, this remains during existence. 

S. In the fetus, the parietes of the ventricles of the brain are thin, 
its surface has no circumvolutions, and the gray substance predomi- 
nates : these circumstances are similar to what always exist in rep- 
tiles and fishes. The brain, properly speaking, has no circumvolu- 
tions in the mammalia or in birds. The proportion between the gray 
and white substance is greater in animals than in man. The Surface 
of the cerebellum is indented before that of the cerebrum, both in ani- 
mals and in man, since this organ is fissured in several fishes, in all birds, 
and in all the mammalia. 

£. Finally,iboth in the fetus and in the animal kingdom, the organs 
of sense, the appendages of the nervous system, appear very gra- 
dually, and these organs in their development present very great 
resemblances to what occurs in animals. 

c. The intestinal canal is at first closed at its upper and lower 
extremities, as in most of the intestinal worms. The posterior end 
remains closed longer than the anterior extremity, as is seen in several 
zoophytes, where the mouth performs at the same time the functions of 
the anus. At first the intestinal canal is not longer than the body, 
and enlarges gradually ; so too we see, generally speaking, and with 
but few exceptions, that it always shortens as we descend in the animal 
scale. Another analogy also with its mode of development in animals 
is its greater simplicity during the first periods of fetal life ; since then 
there is no distinction between the large and small intestines, and the 
stomach is but slightly distinguished from the rest. The cavities of the 
nose and mouth are at first united, a little later they are only joined 
posteriorly, and finally the want of separation between them is ex- 
pressed by the imperfect union of the upper lip on the median line ; so 
too the posterior part of the palate is constantly closed in birds, the 
velum palati is wanting in these animals and in almost all reptiles, and 
many mammalia have a hare-lip. While the teeth develop themselves 
very late in the embryo, they never appear in several mammalia, in 
birds, in many reptiles and fishes, and in most of the invertebral ani- 
mals^ 1) 

(1) This defect however is more apparent than real, <it least in the mammalia 
edentata and in birds. Thus J. !•'. St.Hilaive has remarked that the lower jaw iu the 
fetus of the whale is channeled by a deep fissure, where he found the i udirncnU of 

Vol. f. 7 



50 GENERAL ANATOMY 

During the first periods of fetal existence, an appendage is attached 
to the ileum, which traces the communication existing anteriorly with 
the umbilical vesicle. This communication always remains in many 
birds. Finally, the liver diminishes in size, while the spleen enlarges 
from the first period of the existence of the fetus— phenomena perfectly 
similar to those found in animals. 

d. The sexual parts are at first constructed after the same type, and 
their primitive form is that of the female.(l) Afterwards arrives a period 
when some of these organs, particularly the external, resemble the 
male form, in all individuals, at least in volume. So several zoophytes 
and mollusca have only one ovary, which in the former, as in the fetus, 
does not open externally. The testicles of the male fetus remain for a 
long time in the abdomen; an arrangement, which is the case during 
life in all animals, if we except some mammalia. The uterus, in 
its development, passes through those forms which are permanent 
in the animal series; in fact at first it has long horns, which re- 
semble the separation of the oviducts in reptiles and fishes, and 
in most mammalia, and reminds us of the great length of the internal 
horns, in proportion to the body of the organ ; these horns shorten, 
then the fundus of the uterus is somewhat deepened. Finally the neck 
is very long and thin in proportion to the body : the same as the horns 
of the uterus gradually become smaller in the animals allied to man, 
and the uterus of many of the apes differs but little from that of the 
female, except in being thin and narrow. The external genital parts 
appear late, as in animals. 

e. The urinary system, one of those which is formed very late in 
the animal series, since it is not distinctly seen until we arrive at the 
fishes, does not appear very early in the fetus. The kidneys are at 
first united, as in most fishes and many reptiles : they are also lobed as 
in almost all reptiles, in birds, and in many mammalia. The number 
of lobes is greater and their size smaller, the younger the fetus is, as is 
also seen in fishes, birds, and the cetacea?, and in the superior mam- 
malia. The kidneys are generally larger in the last three classes of 
the vertebrated animals than in the mammalia ; but also in the newly 
born infant they are much larger in proportion to the size of the body 
than at subsequent periods. We find the capsular renales very much 
developed in some of the mammalia, particularly in the order of gnawers, 
which also present other analogies with the proper organization of the 
fetus. 



teeth in a substance analogous to that of the gum : these rudiments seemingly dis- 
appear early ; for then the fissure closes, and the bone fills up. This anatomist has 
also recognized in birds the existence of rudiments of teeth reduced to pulpous nuclei, 
which secrete the horny substance of the beak instead of the phosphate of lime. The 

same arrangement exists undoubtedly in reptiles of the order chelonia. Systime 

dentaire des mammiferes et des oiseaux, sous Ic point de vue de la composition et de 
la determination de chaquc sorte de ses parties, Paris, 1824. F. T. 

(1) Muller, De genitaliumevolutione, Halle, 1815, p. 6. D. de Blainville, Remarque* 
siir leg organes genitaux, in the Bulletin de la societe philomatiqne, 1818, p. 155. 



GENERAL LAWS OF FORMATION' 51 

/ The thymus gland, which in its vital periods is similar to the 
capsulee renales, appears late in the fetus, as in the animal kingdom. 
The mammalia are the first in which it is seen unequivocally ; but it 
soon after acquires a considerable preponderance, and when the fetus is 
formed it resembles, in this respect, the gnawers, the amphibious ani- 
mals, and several plantigrades, in which the thymus gland always re- 
mains fully developed. 

The thyroid gland is at first formed of two lobes only, which are per- 
fectly distinct, as in most mammalia. 

g. The osseous system presents very remarkable analogies, viz. 
first, in the late period of its development. Most of the other systems 
are formed when the bones have acquired only a cartilaginous con- 
sistence. So, too, almost all the organs are developed in the vertebral 
animals before we see the skeleton. When the skeleton shows itself 
for the first time in the cephalopoda,(l) the part first formed corresponds 
to the bones of the head, which are also the first to ossify in the fetus. 
But in the former case the skeleton always continues cartilaginous ; 
so, too, a number of fishes are called cartilaginous, by which is meant 
that their osseous system always exists in the state of cartilage ; and 
in other animals of this class, as also in the reptiles, the bones never ad- 
vance from the temporary conditions of fetal life, i. e. they alwaj^s 
remain softer than in animals of the upper classes. In the higher ani- 
mals the texture and composition of the bones in the early periods of 
life form a second analogy between man and animals. A third comes 
from their external form. There is not a single bone which, in the 
course of development, does not pass through some of the forms which 
are permanent in animals. This proposition is true, especially in regard 
to the bones of the trunk and head. In fact the pieces which gradually 
unite and form the vertebrae, the occipital bone, the temporal bone, the 
ethmoidal bone, the sphenoidal bone, the frontal bone, and the upper 
and lower maxillary bones in the fetus, always remain distinct and sepa- 
rate in most animals inferior to man ; and the first periods of fetal 
existence correspond to the formations, which are permanent when we 
descend in the animal scale. 

h. The external form of the fetus also passes through several inferior 
formations. The want of distinction between the head and the trunk, 

(1) J. F. St. Hilaire thinks that the articulated animals, which form one of the 
great divisions of the invertebrata, also have a skeleton,. but it is placed externally, 
instead of internally as in the vertebrata : he compares the rings of their bodies to 
vertebra and their feet to ribs. (See J. F. St. Hilaire, Mem. sur un squelette chez 
les insectes, dont toutes les pieces identiques cntre elles dans les divers ordres du sys- 
time entomologique, correspondent a chacun des os du squelette, dans les classes su- 
perieuree; in the Jour, compl. du Diet, des sc. med., vol. v. p. 140.— Id. Mem. sur quel- 
ques regies fudamentales en philosophic naturelle, same collection, vol. vi. p. 56.— 
Id. Rapport surun Memoire d' Audouin, concemant I' organisation des insectes, ibid, 
vol. vi. p. 36.— Id. Mem. sur une colonne vertebrate et ses cotes, dansles insectes api- 
ropodes, same collection, vol. vi. p. 138.) This opinion has been adopted by Rudolphi, 
(Beytragc zur Anthropologic, 1812, p. 89,) and by Cams, [ZeUschnflJur die ]\atur 
und Heilkunde, vol. ii. p. 308, 1822 ;) it is well developed in the Dictionnan-e c/as- 
sique d'histoire naturelle, vol. v. p. HI., article Crustacea, F. T. 



52 GENERAL ANATOM1 

itself destitute of ihe extrenut.es, is manifest in worms and the mollusca, 
as also the want of the neck after the limbs arc developed assimilates the 
fetus to fishes and the cetaceae. Many fishes, many reptiles and even 
the cetacean among the mammalia, also want one or the other oi trie 
two pairs of members, and where the limbs appear for the first time in 
the animal series, they are merely stumps, without fingers or toes, as 
when they are first seen in the fetus. In no animal is the number of 
fingers greater than in man, and in many it is less. In many the toes, 
although the same in number as in man, are, to a certain extent, united 
by a swimming membrane ; this is another analogy with the human 
fetus, where the fingers and toes are at first joined together, although 
one easily perceives that they constitute so many distinct parts. The 
vertebral column evidently terminates at first in a small prolongation, 
similar to a tail. 

15th. Man is distinguished from the, other animals by the greater 
rapidity with which he passes through the inferior formatioms. As his 
organization is the most perfect of all, he rises above the inferior degrees 
more rapidly than other animals, doubtless in order to gain time to 
arrive at his highest perfection^ 1) 

§ 29. IX. Although the form of the human organism varies at different 
periods of life, yet it presents certain peculiarities which distinguish it 
from all others, and characterize the human race as a separate species. 
This species, however, is only one of the numerous modifications of the 
primitive type which constitutes the base of all animal formations, so 
that its form necessarily resembles, in many respects, those of other ani- 
mals, particularly those most allied to man. It is then almost incredi- 
ble that, even recently, several writers would consider many of these 
conditions of the human form not as results of this law, but as proving 
positively that, after the original sin, man was even physically degraded 
from the great excellence he possessed in Paradise ! They pretend that 
the traces of the intermaxillary bone prove that the cerebrum and cra- 
nium are diminished ; they add, that the face is developed in the same 
proportion, that the plantaris muscle has attained at the same time 
the aponeurotic expansion of the sole of the foot, and that its actual rudi- 
mentary existence proves that men then walked on all fours, &c. All 
these assertions are unfounded : all these phenomena demonstrate 
nothing, since it might be proved in the same manner, by the arrange- 
ments of some other part, that man, before the deluge, was a different 
animal from what he is now. The human structure has nothing to 
distinguish it entirely from that of animals : it ought then to have the 
same forms : those presented by it serve to remind us, here and there 

(1) This law should be called the law of Harvey ; for, although it was long- for°-otten 
and lias been completely developed only by the moderns, it was, however ifarvey 
who founded it, in saying : Est cquidem, quod miremur, animalium omnium (puta 
ranis, equi, cervis, bovis, gallince, serpentis, hominis deniquc ipsius) primordia lam 
plane galbafiguram el consislentiam re.ferre ut oculis internoscere neqveas (De 
generation, Amsterdam, 1662, p. 77.) This law is of general application to the whole 
organic kingdom. We must, however, distinguish it from the false law of Harvev 
of which we shall soon speak. "' 



GENERAL LaIVS OF FORMATION. 53 

of what is found in animals. But these marks, such for instance as the 
intermaxillary bone, are easily explained by the preceding law ; they 
trace that series of degrees of the organization through which the em- 
bryo, but not the whole human race, always passes ; or they are the 
vestiges of the primitive state when the human formation was depressed 
to the level of the animal formation. In order to give some probability 
to the opinion we oppose, it is necessary, at least, to compare the hu- 
man skulls before the fall of man and the deluge with each other, and 
with those of the present time.(l) Nor are there any facts to support 
a similar hypothesis, the partizans of which pretend, that as the 
human organism, in accordance with the preceding law, passes through 
different periods, so this is the case with* the whole human family ; and 
that certain races are now at a point formerly possessed by other races 
at present more elevated, and that these also are capable of gradual 
improvement. (2) In refuting this hypothesis, we cannot deny but that 
the different classes of organisms are developed gradually, and in 
direct proportion to their greater or less degree of perfection. 

To determine the special conditions of the human organization, we 
can bring together the characteristic marks which distinguish it, so 
far as they depend on the conditions of the forms of the different parts ; 
and also those drawn from the form of the whole body, and use them 
to trace a general picture. (3) 

We become acquainted with the marked characters of the human 
organization, by studying, successively, the different systems and the 
different apparatuses. 

Nevertheless, before proceeding farther, we should observe, that 
most of these characters distinguish man only from those animals 
which are the nearest to him, as the other mammalia. 

1st. The mucous tissue of man differs from that of almost all other 
animals by its greater softness; perhaps the power he possesses of 
living in all parts of the world, and the frequent anomalies presented 
by his organization depend on this. 

(1) The following passage from Ackermann, (De natures humanee dignitate, Hei- 
delberg-, 1813,) will show that we have not misrepresented him, as is, uuhappily, too 
often done : " Fuere lempora, qua antediluviana dicimus, ubi ita despecta et abjecta 
erat humana species, ut brutorumanimantium natures non eequivalcret lantum, sed 
et infra earn deprimcretur. Argumenta ultra omne dubium elata nobis exhibet ana- 
tomica corporis humani perscrutatio. Rcperimus enim per totum corpus non rara 
vestigia degenerates in brutorum naturam humanee fabrices, ita ut inter nvultasra- 
riores excitem species... Os inlermaxillare, aperto indicio : aliquando in homine 
maxillas, uti in brutis magis versus anterior a protrusasfuisse, cranii reccdentis am- 
plitudine diminuta... Musculus plantaris pedis... argumento, [aliquando hominem 
extremis digitis incessisse quod aliomodo fieri non potuit, nisi etiam priore extremi- 
tate corpus suffultumfuerit." Who is not reminded of Stephanus and Sylvius 1 

(2) Sec Schelver's Memoir " On the primitive race of the Human Family," in 
Wiedemann's Archiv fur Zoologie und Zootomie, vol. iii. p. 1. No. 4. Sehelvcr and 
Doornik pretend that all the races are formed by gradual improvement from the negro 
race. Pallas had already presented this opinion as a probable hypothesis. P. T. 

(3) The distinctive characters of the human race have been well defined by Blu- 
menbach, {De Generis humani varietate nativa, Goettingen, 1795, p. 4. 4(* ) — See 
also W. Lawrence, Lectures on Phys. ZooL, and the Nat. Hist, of man, republished 
at Salem, 1828.— Caldwell, Thoughts on the Original Unity of the Human Race, 
New York, 1830. 



54 GENERAL ANATOMY. 

2d. The vascular system. The obliquity of the heart, the inclina- 
tion of its apex to the left, and the adhesion of the lower face of the 
pericardium to the centre of the diaphragm, are characteristics of man, 
or at least are possessed in common with him only by a small number 
of apes, which resemble him very much. 

There are but few animals, too, in which the vessels of the head 
and superior extremities arise, as in man. The distribution of the 
vessels is not the same ; we distinguish the want of the rete mirabile 
i. e. of a plexus formed by the internal carotid artery before entering the 
eye ; if this be not peculiar to man alone, it serves to distinguish him 
from a great many animals. We may also mention here, the arrange- 
ment of the thyroid arteries, which are two on each side in man, while 
in the other mammalia we find only one, &c. 

3d. The nervous system of man differs from that of other animals 
in the remarkable size of the brain. Nevertheless, as a comparison 
of the brain with the rest of the body does not lead to exact results, 
either when we regard its weight, or consider its volume only, it is 
more convenient to contrast the encephalon with the spinal marrow and 
nerves. In doing this, we find the relation to the brain more favora- 
ble in man than in any other animal ; and we discover that, in him, 
the brain is larger in proportion to the spinal marrow and nerves.(l) 

At the same time the spinal marrow in man is proportionally thin- 
ner and shorter than in all other animals ; since, in him, it occupies 
only the greater part of the vertebral canal, while in animals, with 
few exceptions, it fills all this canal. 

If we compare the different parts of the encephalon, we find also, 
that man is distinguished from all other animals by the greater volume 
and development of the cerebrum in him, which predominates over all 
other parts of the nervous system. 

The upper and anterior part of the brain principally exceeds those 
portions which relate to the organs of the senses. To the first law 
then is attached a second, viz. That the cerebrum, properly speakiag, 
is very much developed in proportion to the organs of the senses. 

There are also, or at least they state as such, other characters pe- 
culiar to parts of the encepholon, viz. 

1. In the brain; the existence of the small calculi of the pineal 
gland,(2) which are not constant except in man, but which exist also in 
the buck, and which are sometimes deficient even in man, as in old 
persons. (3) 

The greater development of the cerebrum, properly speaking, is at- 
tended also with the presence of parts peculiar to man, as a special 
dilatation of the third cerebral ventricle, the third horn, and the emi- 
nence inclosed by this cavity. 

(1) So:mmerring, Von Baue des menscklichen Koerpers, vol i p 85 — J G Ebel 
Observationes netrologica ; in Ludwig-, Scrip, neurol. minor vol lii p 148 ' 

ill }^ ig . n0 } 'rP e laJ ? UiS - Vel r^ e vel in fra gland, pineal, sitis, IVfayence, 1785 
(3) Wentzel, De penitiori cerebri structurd, p. 156. ™ 



GENERAL LAWS OF F0KMAT1ON. S5 

The spinal marrow of man presents this peculiarity, that when per- 
fectly developed, it is completely solid. In other animals we see along 
its centre a cavity, but in man, this does not exist always, being soon 
obliterated. 

. 2. In the organ of sight, a. The vicinity of the eyes which are 
still nearer each other in the ape. 

6. The absence of the membrana nictitans, although its rudiment 
exists in the inner angle of the eye, where it forms a semi-circular 
fold. 

c. The absence of the suspensory muscle of the eye, a character 
which belongs also to the apes, but which, with this exception, dis- 
tinguishes the organization of man from that of all other animals. 

d. The existence of the eyelashes, although these are found in some 
mammalia, and also in some birds. 

3. In the organ of hearing, a. The existence of the lobe of the 
ear, which is also seen in some apes, but in them it is much smaller. 

b. The immobility of the external ear ; this last, however, is not 
general, and is seen only in civilized people, and may be ascribed to a 
want of exercise : on the other hand it is common also to the ant- 
eater. 

4. In the organ of smell, a. The projection of the nose over the 
mouth, and generally its prominence, a character to which, notwith- 
standing its generality, the simia rostrata is an exception, not to men- 
tion the trunk possessed by several mammalia. 

b. The want of an organ like a sack, which has been lately disco- 
vered in all the other mammalia on the floor of the nasal fossae, and 
necessarily the absence of a communication between the buccal and 
nasal cavities, the foramen incisivum, which always exists in the other 
mammalia.(l) 

c. In the organ of touch. The smoothness of the skin, which arises 
from the fewness and shortness of the hair. It is well proved that no 
part of the skin of the ape is more naked than that of man ; but the 
skin of the cetacese is undoubtedly less hairy than the human skin. 
The abundance of hair on some of the South Sea Islanders approxi- 
mates the skin of man to that of the other mammalia. 

4. The osseous system. 

1. In the head we remark, 

a. The proportion between the skull (cranium) and the face (fa- 
des) . ( 2 ) The excess of the former over the latter distinguishes the hu - 
man organization from all others. It exists because the brain is much 
greater in proportion to the other parts of the nervous disposition, espe- 
cially the nerves and the organs of sense, as the skull is designed par- 
ticularly for the brain, while the organs of the senses of sight, smell, 
and taste, are situated in the face. We may also separate from the 

(1) See the Description of an organ observed in the mammalia by Jacobson, con- 
firmed by Cuvier, in the Annates du Museum, vol. xviii. p. 412—24. 

(2) G. H. C'rull, Diss, de cranio ejusque adfaciem rations, Groningen, 1810- 



56 GENI'.RAI. ANATOMY. 

brain-case that pari, of the head designed for the organ of hearing, 
inasmuch as the temporal bone which contains it is situated at the 
base of the skull ; and secondly, its squamous portion, which is appro- 
priated to the sense of hearing," is always separated from that part, and 
concurs to form the brain-case ; thirdly, the Eustachian tubes unite 
the organ of hearing with the buccal cavity, consequently with the 
other organs of the senses. This mode of considering the subject is 
justified still more by comparative anatomy. 

The skull also exceeds the face in size, from the predominance of 
the brain over the organs of mastication, with which the greater 
development of the organs of taste and smell coincides. The projection 
of the jaws forward and the retreat of the forehead, which is a conse- 
quent of it, have given rise to the facial angle of Camper.(l) This 
angle is formed by the union of two lines, one of which, called Cam- 
per's facial line, descends from the most projecting part of the forehead, 
along the edge of the upper incisors, and the second is parallel to the 
base of the cranium, and passes by the external auditory passage and 
the inferior edge of the nasal passage. It is evident that as the jaws 
retreat, and the forehead projects, the angle enlarges, although for 
several reasons it does not indicate precisely the relation of the face to 
the skull considered as the brain-case. 

b. The situation of the occipital foramen. In man this foramen is 
found exactly or very nearly in the centre of the base of the skull ; so 
that the centre of gravity of the head corresponds to its centre of mo- 
tion when the head rests on the base of the skull : a circumstance very 
important in regard to the question of the erect posture of man. (2) 

c. The arrangement of the "upper jaw. Its anterior and internal part , 
in which the incisors are inserted, constitutes in animals, with the ex- 
ception only of some apes, a bone, which remains distinct through life, 
and is called the intermaxillary bone, (os incisivum s. intermaxillare.) (3) 
This portion however is entirely separate from the rest of the bone in 
man also, but only during the early periods of existence ; and in the 
intermaxillary fissure we can always trace more or less evidently the 
peculiar formation of animals. (4) 

d. The shape of the chin, which in animals retreats more or less 
behind the alveolar processes, while in man it projects slightly before 
them. 

(1) P. Camper, Diss, surles rarietes naturelles qui caracterisent la physionomic 
ties hommes des divers climats et d<$ differens ages, translated by Jansen, Paris, 
1791 .—See also Stuart, De mensch, zoo als hij roorkomt op den bekenden aardool, Am- 
sterdam, 1802, p. 51.— Wiedemann in Archiv fur Zoologie und Zootomic, vol. i. part 
1. p. 18.— J. E. Doorniek, Wijsgeerig natuurkundig onderzoek aangaandedenoors- 
sprongliken mensch en de oorsprong like stammen van deszelfs geslacht Amsterdam, 

loOo. 

(2) Seethe memoir of Daubenton, Sur Irs differences de la situation du grand 
Lrou occipital dans I'homme ct dans les animaux, in Mem. de I' Academic des sciences 
1764, p. 568 — 575. F. T. 

(3) G. Fischer, Ucbcr die. terschiedene Form des Intcrmaxillarknochcns in ver- 
schiedenen Thicren, Letpsick, 1800. 

(4) Goctlie, Zur Naturwisscnschafl ubcrhaupt, insbesondcre zur Motuhnlntrir 
Stuttg-ard, 1820, p. 201. -uorpnoiogic, 



GENERAL LAWS OF FORMATION. 57 

e. The position of the teeth, in two respects : 

a. These bones in man form an uninterrupted series, while in ani- 
mals, except the anoplotherium,(l) we always observe a vacuum, 
caused either for the greater development of the canine teeth or by 
their absence. 

/3. Man is almost the only animal in whom the direction of the in- 
cisors is perpendicular to that of the two jaws. 

2. The trunk also furnishes some distinctive characters : 

a. The pelvis in man is peculiarly formed. With a few exceptions, 
the human pelvis is the only one which appears as a low, spacious 
cavity, surrounded by broad parietes, or as the bottom of a reservoir. 

6. In man also the bones of the vertebral column, from above down- 
ward, increase considerably in volume, although generally the spinous 
processes, particularly of the thoracic vertebrae, are proportionally 
shorter than in animals. 

c. The sternum. When man is perfectly developed, the sternum is 
formed at most but of three bones ; while in the other mammalia its 
parts are very numerous, equaling the number of spaces between 
every two true ribs ; an arrangement which is also regular in man at 
certain periods of life. 

5. The muscular system in man differs from that of other animals by 
the slight development of some muscles and the greater power of 
others. 

The muscles least developed are those which move the skin ; the 
most vigorous, on the contrary, are those which serve to maintain 
the erect attitude, and those which prevent the inferior part of the 
trunk and the lower extremity of the thigh from bending forward, that 
is, principally those of the haunch and of the calf of the leg. The 
muscles which move the head are also more developed in other mam- 
malia, both on account of their proper attitude, and because they serve 
to sustain the head, and to bite. 

The composite systems and apparatuses present the following pecu- 
liarities : 

1st. In the intestinal canal, the vermiform appendix of the ccecum 
is in some measure a distinctive character of the human formation. 
But the vesicula umbilicalis is not confined to man only, since the 
tunica erythroides which is found in all the mammalia, at least at cer- 
tain periods, and the vitelline sac of birds, reptiles, and of many and 
probably of all fishes, correspond to this organ. 

2d. In the genital apparatus, the separation which takes place soon 
after birth between the serous sac of the testicles and the peritoneal 
sac is a character which belongs exclusively to the male ; for the canal 
of communication between these two cavities is never obliterated in the 
other mammalia. In the female, the external form of the womb, the 
tissue of this organ, and the presence of the hymen, have been consi- 
dered as so many particulars belonging exclusively to the human 

(1) Cuvier, Ann. du Museum, vols. iii. and ix. 
Vol. I. 8 



58 GENERAL ANATOMY. 

race ; but this is false in regard to the hymen, which has been found 
well developed in several other mammalia, or at least is always indi- 
cated by folds.(l) The other two characters are more valuable : 1. 
In fact the womb of most mammalia is not single and pynform both 
externally and internally, like that of the female ; but it has two horns, 
and frequently is completely divided into two cavities. 2. It has also 
a distinct red layer of muscular fibres, which is attached to the internal 
membrane only by a loose cellular tissue, and its parietes are very thin 
in proportion to its cavity, while the fibrous texture of the human ute- 
rus is developed only during pregnancy ; even then the fibres of this 
organ do not assume the peculiar appearance of those of the muscles : 
it is difficult to separate the internal membrame from the rest of its tis- 
sue ; and its cavity is always very small in proportion to the thickness 
of its parietes. 

Neither are these conditions exclusively peculiar to the human race ; 
for they are found in almost all the edentata and tardigrada ; besides, 
the womb of the apes and makies differs but little from that of woman. 

§ 30. The principal character of the human species is drawn then 
from the large size of the brain, from the inferior development of the 
organs of sense, and their almost uniform development. 

It is in this sense only that we can admit the proposition of Her- 
der(2) so often repeated by others, that man is but a species interme- 
diate between those beings above and below him. 

§ 31. From the many particulars already mentioned, and from those 
which remain to be examined, may be deduced a fundamental charac- 
teristic of the human species, viz., that originally, and from his very 
nature, man was formed for the erect posture. The ancients understood 
this law perfectly well, and showed more sagacity in. developing it 
than many modern writers have in opposing it. (3) 

§ 32. X. Notwithstanding the peculiarities of conformation which 
prove that man, like every other organism, forms a separate species, 
daily observation demonstrates that, under any relation, all the indivi- 
duals are not exactly alike. 

The principal difference, which extends to the whole species, is 
the distinction of this species into two sexes,(4) male and female. This 
in fact does not exist, or is not marked so distinctly, in the early periods 
of fetal existence ; and as the resemblance of the organism to itself is 
much greater the nearer it is to the time of its origin, so at this period 

(1) Cuvier, Anatomic comparee, vol. iv. 

(2) ldeen zur Philosophic der Geschichte der Menschheit, Carlsruhe, 1790 vol. i. 

(3) Compare Moscati, Dellc corporeeldifferenze esscnziali che passano tra la strut 
turade'i bruti e la umana, Milan, 1770; and against his assertions G Vrolik Dc 
komine ad statum gressumque rectum per corporis fabricam disposito Levden 1795 
— G. Bakker, Natuur-en geschiedkundig onderzoek aangaande den oorsnronkiiken 
stam van het menschelijk geslacht, Harlem, 1810.— The opinion of Moscati has been 
maintained by Schelver and Doornik, and contested by Blumenbach, Herder Vrolik 
and Bakker. ' Tlulm > 

(4) HufelaneZ, Sur V egalite numeriquc des deux sexes dans I'espue humaine in th*> 
Jour, compl. du Diet, des Sciences Med., vol. vi. p. 361. '^maine, in the 



GENERAL LAWS OP FORMATION. 59" 

all the organisms appear formed more exactly after the same type 
But this difference soon begins to show itself, and although the sexual 
characters in the general form are not well marked until after the four- 
teenth year, nevertheless the form of some organs, as the genitals, in 
the regular course of development soon assumes the characters of the 
male or female. The two sexes differ from each other both in the size 
of the body in general and of the organs in particular, and also in the 
proportion either between these organs themselves or between them 
and the whole body, as in regard to their external form and texture^ 
physical properties, and the position of their parts. 

1st. hi size. The male is usually taller than the female. Some 
organs are proportionally larger in the male, and others in the female. 
Besides the differences in this respect between the different parts of the 
genital organs, for the mammae of the male are less developed than 
those of the female, and the uterus is larger than the prostate gland, 
and again, the testicle is more voluminous than the ovary, and the 
penis than the clitoris : independently, we say, of these differences, the 
heart, lungs, and organs of voice are larger in the male, while the liver, 
and the brain considered proportionally to the nerves and the whole 
body, are larger in the female. The hair of the head is more deve- 
loped in the female than in the male ; in the latter there is a strong 
beard, and the whole body is hairy, which is not the case in the female, 
except on the head and pubis. 

2d. In the external form. The number of parts is the same in the 
female, but they differ somewhat in form, for if the stomach in the female 
is more oblong, and in the male rounder, the form of the body of the 
female, and usually that of all the organs, is rounder than in the male 
where the outline is sharper and more angular. 

In fact all the parts of the genital apparatus correspond in the two 
sexes ; but their external forms vary so much that it seems at first im- 
possible to believe that the genitals of the two sexes are only modifica- 
tions of the same primitive type. In this respect the distinguishing 
characteristic is the predominance of length in the male, and of breadth 
and thickness in the female. It is seen both in the form of the genital 
organs and in that part of the body which contains them. Thus the 
male pelvis is narrower, more contracted, and deeper, than that of the 
female ; the penis is longer and narrower than the vagina and clitoris, 
the vasa deferentia are longer than the Fallopian tubes. The two sexe3 
differ also as respects their constancy of form, which is much greater 
in the male than in the female. 

3d. In texture and physical qualities. The body of the female is 
usually more delicate, softer, and less firm than that of the male. 

4th. The situation of the parts is the same in both sexes, if we ex- 
cept those organs which relate to the generative functions. The prin- 
cipal difference in this respect bet weep the -male and female is, that 
the parts are external in the male, but internal in the female. The 
testicles are situated externally, and the ovaries internally, the pros- 
tate is at the outlet, and the uterus within the cavity, of the pelvis ; the 



60 GENERAL ANATOMY. 

penis extends along its external face, while the clitoris and vagina are 
placed within its cavity. 

§ 33. Besides this grand fundamental difference, which divides the 
human species into two halves, there are others less striking which are 
common to both of these halves, which distinguish the species, not into 
sexes, but races. They are called, differences ofraces.(l) 

The characters employed to establish the principal divisions of the 
human family may be very different, but the suitable track to follow 
is that which embraces the whole organization, and is not confined to 
the consideration of only one or another of its peculiarities, as, for exam- 
ple, the color, size, the proportions of the different parts of the body, &c. 

Buffon was the first who proceeded in this manner, and divided man- 
kind into six races, viz. the Hyperborean, or Laplander, which in- 
cludes the polar nations : 2d, the Tartar, which is the largest, and 
inhabits central Asia : 3d, the Southern Asiatic, which embraces also 
the South Sea Islanders : 4th, the European : 5th, the Ethiopian : 
and 6th, the American: (2) but, finally, he reduces these six races to 
five only, considering the Laplanders as degenerated Tartars, and in- 
dicating very precisely the tribes which make the transition from the 
Tartar race properly so called, to those imperfectly developed nations 
who live under the poles. 

After this correction, the five races established by Buffon, correspond 
to those of Blumenbach, as the Laplander and the Tartar of the first 
are the Mongolian of the second ; the Southern Asiatic corresponds to 
the Malay, and the European of Buffon is the Caucasian of Blumen- 
bach ; the similarity of names identify the other two. 

§ 34. The principal characters which distinguish the European, or 
the Caucasian, race from the others, are as follows : 

A white skin, but in the people of the south it is brownish yellow ; 
cheeks red, but they have little or no color in the other races. The 
color of the hair varies, from a light yellow to a deep brown, and even 
black. The eyes, that is to say, the irides, are blue, gray, brown, and 
rarely entirely black. The form of the face is oval, neither very flat 
nor very angular. The bones are no where very prominent ; neither 
do the cheek bones ever project much. The forehead is arched, but 
never retreating ; the nose narrow, the mouth moderately large. The 
lips do not project much ; the lower projects beyond the upper. The 
teeth are perpendicular to the two jaws. The chin is full and rounded. 

(1) The principal work on this subject is that of Blumenbach. De generis humani 
varietate nativa, Goettingen, 1795. Consult also, besides the work of Herder quoted 
above, A. G. Zimmermann, Geographische Geschichte der Menschenundderallge- 
memverbreiteten 7W, Leipsick, 1778-1783. G. Josephi/ Grundriss der Naturge,- 
chichte des Menschen, Hamburgh, 1799.-C. F. hn&vhg Gundriss der Naturges- 
chxchte desMenschenspecies, Leipsick, 1796.-J. J. Virey, flwtofre naturelle dugfnre 
humain, Pans, an 1X.-U JRecherches sur Z«j nature et les families de ffwmme.- 
L. Gross, Magazmfur dieNaturgeschichte des Menschen, Leipsick 1788- 1791 — S 
S. Smith, An essay on the causes of the variety of complexion and figure in thr hit' 
man species, nth* American Museum 1789, p. 30, et seq.-C. Meinerf, Vntersuchun- 
gen uber die Verschiedenheiten der Menschennaturen, Tubingen 1811 

{2) Histoire naturelle, vol. iii : Histoire naturelle de I'homme. Variites dans I'es- 

p€CC rlUTTlCitnCj D. 01 • 



GENERAL LAWS OF FORMATION. 61 

The Caucasian race represents, in some measure, a centre, on each 
side of which are varieties. In fact, the head, and to a certain extent, 
the whole body becomes either broader or narrower. The Mongolian 
and American races are marked by greater breadth, while a lateral 
compression is seen in the Ethiopian and Malay races. 

The principal characters of the Mongolian race, are a yellowish or 
olive color, between that of wheat and boiled quinces or dried lemon 
peel ; hair black, short, thin, stiff, and straight ; head almost triangular ; 
face broad and flat ; cheek bones high and prominent ; forehead very 
broad and flat ; small flat nose ; cheeks almost round, and plump ; 
eyelids half closed. The proportion of the skull to the face, is a little 
less favorable than in the Caucasian race, being about one tenth less. 
The stature of the northern nations of this race is very low ; the ex- 
tremities are very short, even in the countries at some distance from the 
north, which probably depends in part on artificial habits. 

The American race is distinguished from the others by a copper or 
cinnamon color ; hair fine, black, straight, and thin ; forehead low ; 
eyes sunken; nose slightly flat, although projecting. The face is broad ; 
the cheek bones are generally prominent, but the different features are 
not both flat and depressed ; they appear, on the contrary, very full, 
especially on a side view. 

In the Malay race the skin is brown ; the hair is soft, curled, and abun- 
dant ; the head narrow; the forehead prominent ; the nose broad, diverg- 
ing, and thick at its apex ; the mouth large. The upper jaw projects 
considerably ; but on a side view the features are well proportioned. 

The Ethiopian race is farther removed from the Caucasian in many 
respects. The color is more or less black ; the hair is short, thick, 
woolly, fine, hard, glossy, and elastic : it does not extend itself gra- 
dually towards the neck, but terminates suddenly, like a wig. The 
eyebrows are also curled and thinner ; the eyelashes are much more 
arched and thicker than in the other races. But these peculiarities are 
not seen at all periods of life, for at birth the color is whitish, and the hair 
is long and curled, but not woolly, and on the back part of the head it 
continues insensibly to the neck ; this latter is stronger, and the occiput 
is more feeble ; the occipital foramen is placed a little farther forward 
and is larger ; the head is narrow and compressed laterally, whence 
the forehead appears sloping. The cheeks project forward, but 
not on the sides ; the upper jaw is constructed after the same type, 
and the cheek bones project, evidently, from this arrangement. Hence 
the alveolar processes appear narrow and long. The upper incisors 
are directed obliquely forward. The bones of the skull are very strong 
and very thick. Of all the human races, the Ethiopian is that in which 
the proportion between the face and skull is least advantageous to the 
latter, for the facial angle is only seventy degrees, while in the Mongo- 
lian race it is seventy-five, and in the Caucasian, eighty. The surface 
of the face, compared to that of the skull, is one fifth larger in this race 
than in the Caucasian. The nerves, especially those of the first, second, 
and fifth pairs, are also more voluminous, in proportion to the brain. 
The brain is firmer. "We could discover no difference in its color, and 



62 GENERAL ANATOMT. 

the various opinions among authors on this subject leave it doubt- 
ful. The lips, especially the upper, are thick and turned upward ; 
their color is not purely red, but they are bluish black, or at most a 
dirty rose-red. The chin is more or less retreating. The nose is very 
thick, and is almost blended with the upper jaw, and it is, moreover, flat, 
even in young fetuses. The eyes are very prominent, and often so 
black that, in many nations of this race, we cannot distinguish the 
iris from the pupil. The aperture of the eyelids is generally smaller 
than in the Caucasian race, but the globe of the eye is larger, and 
blackish to about half a line round the cornea, while the rest is yellowish. 
The rudiment of the third eyelid is greater than in the other races. 
The external ear is rounder, more analogous to that of the ape, and 
stands out farther from the head. The muscles of the mouth are 
more developed ; hence the temporal fossa is deeper, and the semi- 
circular line on the side of the skull is more distinct and prominent. 
The anterior orifice of the nasal fossae is extremely large, and the sur- 
face of the pituitary membrane is increased by some irregularities within 
the nose. The anterior palatine foramen is broader. The teeth are 
very large and very broad. The pelvis is narrower than in the Euro- 
peans. The hands and feet are well proportioned, but fiat ; the fingers 
and toes are long. 

The genital organs in this race present some general peculiarities, 
and some characters which belong only to certain tribes. They are 
chiefly characterized by their great development ; in males, this is seen 
in the size of the penis, and in that of the clitoris in females.(l) The 
nymphae are sometimes (2) excessively lengthened, and sometimes, in 
different nations, even new parts seem to be developed, certain acces- 
sory organs, which serve to enlarge the external genital apparatus. (3) 
All these peculiarities are very remarkable, because they resemble the 
structure of the ape. In fact, the Ethiopian race seems to form the 
transition from the Caucasian race, to the quadrumani.(4) 

§ 35. The number of races can be restricted still farther, by referring 
to a single type, those which are separated in the same manner, 

o WJfrUlant's Travels in the Interior of Africa, in the Mag. merk. Rtisebcschr,vo\ 
2. p. 308. ' 

(2) Peron and Lesueur in the Anatomie Comparee of Cuvier vol iv —Barrow in 
Voigt's Magazin fur die Naturlehre, vol. iii. p. 4. p. 792. Barrow, however, 
pretends that the parts found in the Boschisman woman are prolongations of the 
nymphse. r ° D 

(3) The exhibition of a Boschisman woman at Paris as a Hottentot Venus who died 
there, proved that Peron was deceived in admitting a special organ. The pretended 

dtoHvedoI llTnTu LtnS onl^tolhe Hn Hottentots > <« the true HottKs are 
deprived ot it, and it belongs only to the Houzouanas, or Boschisman women } is 
a prolongation of the nympha;, developed, if we may so sneak nt ih.Tr.lZ ° mel YJ 
labia externa, which are hardly visible Cuvier has s Ef\h « iu ex P ensc ol the , 
the two fleshflobes which compose this apron, are orltdTr^tt^eZ^ ^ 
summit of the nympha;, while the rest is only an extension nfihl P re P uce a J? d * h . e 
Memoir on this subject, in the Memoires du Iw^cumZ iif „ I^Tfr- ^^ 
tice sur la Vinus Hottentote, in the Journal complemen'ta re P W, hjf- loure ? s > ^°- 
s^es nedicales, vol. iv. p. UB.-G. Soa^erJ^^^^^^^ 

J$£uro%Jr] fSSSSCShL*" * ******* ******* ** &* 



trcft 



GENERAL LAWS OF FORMATION. 63 

from the middle term of the formation peculiar to the Caucasian race. 
We should then have only three races. This classification is more con- 
venient, as it is favored by the similarity of customs. Finally, the (lif- 
erent races not only pass from one to the other by imperceptible shades, 
but still it sometimes happens that certain individuals belonging to one 
race, resemble others in many essential respects, and especially in the 
form of the head. We have before us, at the present moment, the skulls 
of several Germans, so strongly marked with the characters of the Ethi- 
opian race, that it would be difficult to distinguish them from the skulls 
of negroes. 

The form of the whole bod}', and especially of the head, evidently 
proves, that the Caucasian race, is that, in which the human character, 
the predominance of the brain, is seen most perfectly, and on the con- 
trary, the Ethiopian race most resembles the apes. The other races 
form intermediate degrees between the Caucasian race and the other 
mammalia. But we have no proof, nor is it even probable, that the 
Ethiopian race can in time be perfected, and that the other races have 
already possessed their form, than that the human race has once been 
formed more perfectly, of which form it is now deprived. On the con- 
trary, there is every reason to think, that the species man was formed 
last, and that all other beings are so many attempts of nature, before 
making him. We cannot decide, whether the different races are con- 
secutive modifications of a single primitive trunk, or if the differences 
be original, and if the number of primitive races,, which perhaps ap- 
peared at the same time, be not infinitely greater than that of the races 
afterwards formed, by including several, similar to each other, in some 
large families ; the second hypothesis however, is more probable than 
the first ;(1) nevertheless, it does not prevent us from reducing the 
five races, actually admitted by naturalists, to three. 

§ 36. Besides the differences of sexes and of races, the human forma- 
tion presents others of a third kind. These latter are separate from the 
first, and are common to the whole species, and are found indiscrimi- 
nately in both sexes and in all the races, although they may be more 
frequent in one sex, or race, than in another : they are called abnormal 
formations, or deviations of formation. In fact, the whole body, as 
well as each particular system, possesses an external as well as an inter- 
nal form, which recurs oftener than any other, and which may therefore 
be considered as the rule. This regular form, is, at the same time, if 
not always, at least in most instances, the most suitable, because it is 
the most favorable for the performance of the functions. It may then be 
called the healthy form, or the form in harmony with the health. On 
the contrary, those which vary from it should be called morbid forma- 
tions ; first, because they often disturb the functions of the organ, and, 
according to the nature of the organ, and the manner and degree of 
the aberration, may even prevent the continuance of life ; and secondly, 

(1) See the memoir of Rudolphi On the distribution of animals, in the Beitrctge 
zur Anthropologic unci allgemeine IS'aturgeschichte, Berlin, 1812. 



64 GENERAL A5AT0MT. 

because the cause of those aberrations from the normal state, is evi- 
dently a disease, as most of the alterations of texture result from mor- 
bid affections. 

These anomalies form the subject of pathological anatomy. Never- 
theless, it is impossible to separate completely the study of the regu- 
lar from that of the irregular structure ; so that general anatomy ought 
to embrace, also, the most important considerations arising from ano- 
malies of texture.(l) 

All the abnormal formations are essentially the same ; in the end, 
they consist in the rarity, and consequently, in a deviation from the 
rule. Nevertheless, these formations may be distinguished from each 
other, either from the size and importance of the organ, or from the in- 
fluence of the anomaly on its function, or according to the degree of the 
anomaly. But the differences they present in relation to the qualities 
of the organs, and to the manner in which they are themselves deve- 
loped, are still more important. 

Many of these anomalies, in fact, affect only the external form of 
the organs ; others their internal structure, their tissue, chemical com- 
position, and physical properties. Many arise during the course of 
life, and are accidental, while others are primitive. Alterations of tex- 
ture are the most frequent, but they are not always accidental. The 
defects of formation are congenital when they do not depend upon 
mechanical injury, or on previous alterations of texture. 

§ 37. The anomalies of form, whether appearing primitively, or after 
the period when the part affected has its regular form, refer, 1st, to the 
number, 2d, to the volume, 3d, to the situation, and 4th, to the form of 
the organs. 

1st. In the first respect, an organ may be entirely or partly defi- 
cient; sometimes the defect is original, but it is often, also, only acci- 
dental, resulting from morbid actions, which, either mechanically, 
chemically, or dynamically, have partially or totally destroyed the 
organ. Thus compression and irritation, arising from tumors, or from 
the teeth which are cutting, cause even the hardest bones, the milk 
teeth, to disappear; by the want of extension, as consequent to a 
ligature, the blood vessels are obliterated as high as the first branch 
furnished -by the trunk, in which the circulation is impeded. The 
acids destroy the most solid parts by solution; the testicles vanish 
without leaving the least trace, and often without any known sufficient 
cause, &c. 

We cannot always determine with precision, if a part which is de- 
ficient, has existed previously, and has been destroyed, since nu- 
merous observations demonstrate, that parts, existing at first partially 
or wholly disappear, not only morbidly, but normally. (See page 46 ) 

(1) These considerations, however, can be pointed out only very briefly when 
treating either of general or o ^escnptive anatotny. We have made them the subject 
of a separate treatise, called Handbuch der pathologiscten Anatomic, Halle 1812-15 



GENERAL LAWS OF FORMATION. 65 

Neither is there an instance of the defect of any part whatever 
which has not been differently explained by different observers. 

The reverse of defect or absence, is a plurality of parts, in which we 
observe numerous gradations commencing with multiplications of the 
small parts. This defect of formation is always congenital, or at least 
the power of the human organism to produce supernumerary parts, is 
extremely limited, except during the period when the normal parts are 
forming. In truth, all these parts are not formed at once. (See p. 45.) 
But if we except those which appear regularly after the others, the 
organism never produces parts in any manner composite, and similar 
to those which exist in the normal state, unless in conditions analo- 
gous to those which the formation of a new organism requires. 

2d. Aberrations in regard to mass and volume, are also congenital 
or accidental. In this case, the mass and volume is greater or less 
than in the normal state, and the increase or diminution in mass and 
volume does not necessarily take place in these two respects at the 
same time. An organ may become much larger than usual, without 
an increase, and even from a diminution in its mass when its tissue is 
considerably dilated or extended. This is proved by the swelling of 
the bones and the dilatation of the hollow organs. 

The abnormal stricture (strictura, coarctatio) of the hollow organs, 
may even entirely efface their cavities ; this is called obliteration, or 
atresia, which has been badly divided into true and false. 

3. Anomalies of situation are accidental more frequently than conge- 
nital. In this point of view, first, sometimes a part is found on the side 
opposite to that where it is generally placed ; or, second, higher or lower 
than usual. Third. Sometimes it is perpendicular when it should be 
oblique, or oblique when it should be perpendicular. Finally, it may exist 
outside of the cavity within which it is commonly found. When this 
part has only left its usual situation, it is called a hernia, or luxation 
(luxatio). Herniaiswhen a part usually inclosed in one of thethree large 
cavities of the body, escapes from it. Luxation is when a bone leaves its 
articular cavity. Inversion is when the internal* face of a .part is 
turned outwardly. Inversion sometimes produces an intussusception 
or invagination, when the inverted part, or those which envelop it, pass 
into another cavity, as happens for instance in the intestinal canal, and 
sometimes it causes a, prolapsus, when these same parts project more or 
less externally. Every prolapsus is, at first, for a longer or shorter time, 
only a simple intussusception, which sometimes lasts only an instant ; 
but an intussusception does not always become a prolapsus. 

4th. Anomalies in form, are produced in various ways ; since the varie- 
ties of which the form is susceptible depend on the particular cha- 
racter it possesses in the normal state. Thus a rounded part can be 
oblong or more angular, and vice versa. A single part may bedivided 
into several others, and parts usually united may be separate and dis- 
tinct. The deviations of formation most often found, are the abnormal 
separation of parts usually united, and the abnormal union of parts 
Vol. I. 9 



66 GENERAL ANATOMY. 

generally separated. But abnormal separation may often, although 
not always, be referred to defect, or absence, as for example, in fissure 
of the palate, or of the abdomen. So too with abnormal union, as 
the fusion of the two eyes into one, the union of the two auricles, or of 
the two ventricles of the heart, &c. 

The anomalies of this class also are accidental, or congenital ; in 
the latter case, they are probably for the most part primitive or ori- 
ginal. 

The anomalies of the first kind, besides those already mentioned, 
are the lobed structure of the spleen and kidneys, the fissure of the 
vagina, of the womb, and of the bladder, &c. 

Those of the second kind, are the different accidental solutions of 
continuity, as lacerations, wounds, and fractures, which may depend 
on an infinity of causes ; the accidental union of parts originally sepa- 
rate, as in anchilosis, &c. 

§ 38. We have already said that aberrations of form are sometimes 
congenital, and sometimes are not developed till after birth. But even 
if one of those anomalies exists when an infant is born, it does not 
thence follow, that it is original, that the altered organ has not been 
well formed at a former period, and that the monstrosity it presents 
does not result from a morbid cause acting upon it before birth. Ne- 
vertheless, irrefutable arguments unite to demonstrate, that congenital 
aberrations of the external form, are also usually original. We can 
refer these arguments to the following, which make us acquainted at 
the same time with the most essential and most remarkable conditions 
of original deviations of formation. 

1. The nature of the deformities announces that they are original. 
In fact, 

a. JVLost of them can be explained in no other manner. Such, for 
instance, as the inversion of all the organs, or of some one only, the 
result of which is, that on the right side we see parts which are usually 
found on the left, and vice versa ; and much more, when the inversion 
takes place, not only in situation, but also in form ; the increase in the 
number of certain parts, as of the fingers and toes ; irregularities in 
the distribution and origin of the vessels, &c. The attempts which 
have been made to account for these anomalies mechanically, are so 
monstrous, that they refute the hypothesis imagined to explain them. 
Organogenesis proves that many deviations of formation, are original ; 
since it can be demonstrated that they depend on the fact, that the or- 
gan has remained stationary at one of those degrees, through which, 
in its normal progress, it successively passes. 

b. The sides of the body seem to differ a little, one from the other in 
regard to the frequency of deviations of formation presented by them. In 
fact, most are found only on the left side. Thus, for instance, the ver- 
tebral artery rarely arises, except on the left side, from the arch of the 
aorta. We see, too, anomalies in the renal vessels of the left side, 
more commonly than in those of the right. To express this law more 
generally, we may say that the regions and the parts which are but 



GENERAL LAWS OF FORMATION. 67 

imperfect representations of parts better developed, or to produce which, 
the formative power seems habitually to employ less energy, are also 
those which vary the most from the rules laid down, and which are 
formed with less constancy. Thus the sternum differs so much in re- 
spect to the number and size of its osseous nuclei, that we can scarcely 
establish any thing certain in regard to them, while anomalies in the 
vertebral column are very rare. So too, varieties in the vessels of the 
lungs, the most noble and most important organ, and which appears 
very early in the animal series, are less numerous and rarer than 
those of the renal vessels. 

Nevertheless, this law has exceptions. Thus, for instance, the dis- 
tribution of the vessels, varies more frequently in the upper than in the 
lower extremities, although the latter appear later than the former. 
But this exception is perhaps only imaginary, as the inferior members 
in the progress of life soon become larger than the superior. 

c. Some systems are more subject to deviations of formation than 
others. The greater part of the nervous, osseous, and muscular sys- 
tems, present anomalies more rarely than the other systems, particu- 
larly the vascular. Among the apparatuses, those of voice and respira- 
tion are less subject to derangement, than those of generation, diges- 
tion, and of the urinary passages. The last two, with the vascular 
system, are those which are most frequently anomalous. In this re- 
spect, there is a remarkable contrast in the nervous system between 
the brain, spinal marrow, and their nerves on one part, and the great 
sympathetic nerve on the other. The difference we have pointed out 
between the different organs certainly depends on this contrast, at 
least in part, since the organs which receive their nerves from the brain 
or the spinal marrow, are distinguished from the others, by the con- 
stancy of their forms. These organs in which the form is most con- 
stant are, at the same time, more symmetrical, so that these two condi- 
tions seem to depend on the same principle. In fact, there is here only 
a simple difference of relation, since symmetry is to the individual, 
what constancy is to the species. 

d. Anomalies of the same organ are similar. Thus, when two 
tongues exist, they are not- placed side by side, but one above the other. 
Anomalies in the large vessels arising from the trunk of the aorta, 
vary much, in truth, but each resembles itself. Thus, for instance, if 
the right subclavian artery does not come from the arteria innominata, 
it arises, most usually, above that of the artery of the left side, and 
there is not merely a division of the trunk of the innominata. When the 
vertebral artery forms a separate trunk, it is always the left which pre- 
sents this irregularity, and itusually rises from between the large trunks 
of the left side, instead of implanting itself below the corresponding 
subclavian artery, although in the preceding anomaly, the origin of the 
right subclavian artery is placed lower even than that of the last. 
The perforation of the septum of the heart, the division of the urethra, 
the contraction of the stomach, always occur in one determined 
place. 



68 GENERAL ANATOMY. 

e. In the anomalies of an organ there is a gradual transition from 
one to another. We can establish a series from the slightest anoma- 
lies of an organ, to the greatest disfigurement of the whole organism. 
Thus the doubling of the whole organism commences by the multi- 
plication of the toes, the heart, the head, and is arrested when two bo- 
dies are united by the head, the chest, the abdomen, &c. So too, m 
monstrosities of an opposite character, there is a perfect gradation from 
the approach of the two eyes, to the existence of only one on the me- 
dian line, with which the anomalies attending it in other parts of the 
head, coincide. We can also trace this transition from the inversion of 
the inferior limbs, to the existence of a single pelvic member, which is 
also central, and developed very imperfectly. This law does not con- 
tradict the preceding ; it only restricts it to a certain extent, and the 
more, as the different degrees of the anomalies of the organs present 
themselves not merely once, but frequently exist in different individuals 
of the same and different species. 

f. The deviations of formation are bounded by certain limits. To 
whatever extent the form of an organ, or of the whole organism, may 
be abnormal, it can always be recognized, even when the organism is 
deformed by several simultaneous deviations of formation. Thus the 
heart is never seen on the back, the lungs in the abdomen, the cranium 
between the lower extremities, &c. These organs then are never ano- 
malous to such a degree, that heterogeneous parts should be blended in 
one mass ; for instance, the nerves with the vessels, the aorta with the 
esophagus, &c. This is one of the strongest arguments against the 
hypothesis, that monstrosities depend on mechanical influences. 

g. Slight anomalies are much more frequent than large deviations, 
both as regards the relation of the volume of the parts, and the influ- 
ence of the anomaly on the functions. The small branches and rami- 
fications of the vessels vary much, while the large trunks are more con- 
stant. It is much more common to see the radial artery arise from the 
brachial artery in the region of the axilla, or the left vertebral artery 
coming directly from the trunk of the aorta, than to see the right sub- 
clavian artery arising below the left, or the aorta divided completely or 
incompletely into three trunks. The rarest anomalies in the circu- 
latory system are those which allow a mixture of the pulmonary blood 
with that of the body, and those which affect the health : as the per- 
foration of the septum of the heart, the origin of the pulmonary artery 
from the aorta, of the aorta from the right ventricle, or of the pulmo- 
nary artery from the left ventricle. This law may be expressed in a 
general way by saying that an anomaly is more frequent the less the 
arrangement of the parts varies from the normal state ; but thus ex- 
pressed this law is not correct : for instance, the perforation of the sep- 
tum of the heart is a normal formation during the first periods of fetal 
existence, and nevertheless it exists much more rarely than varieties in 
the distribution of vessels, which are never normal. 

2. The relations which connect deviations of formation to other condi- 
tions not dependent on the misformed organs themselves, prove that 
these anomalies are original. 



GENERAL LAWS OF FORMATION. 69 

h. The simultaneous existence of several anomalies in the same or- 
ganism. Although but one organ is usually abnormal, a circumstance 
which is connected with the preceding law, nevertheless we sometimes 
find in the same body many which vary from the normal formation. 
The anomalies then present sometimes the same and sometimes a 
different and even an opposite character. Thus, in certain cases all 
the imperfectly symmetrical organs are inverted : those of the right 
side are found on the left, and those of the left side on the right. 
Again, several systems are deformed by a defect of development : often, 
and in fact most usually, some parts are deficient, while others are 
immoderately developed. But we rarely or never find supernumerary 
organs in a body where the general form is characterized by an exces- 
sive activity of the formative power : for instance, a double-bodied 
monster has never more than five fingers and toes. Thus, generally 
speaking, the formative powers appear not to employ more energy 
upon one part unless at the expense of another ; and one part remains 
deficient only because another is too much developed. 

i. The simultaneous existence of several misformed fetuses, or the co- 
existence of a monstrous fetus with one that is well formed. We some- 
times meet with twins or triplets which present similar deviations of 
formation in the same organs, almost always ascribable to a defect of 
development ; and it is more common to find two or three together 
which are monstrous on account of s"ome fault in their development, 
that is to say, in general by defect. A singular relation sometimes 
exists in this respect between one pregnancy and another : a finger, 
for example, which is deficient in one child is found in excess in the 
next. This law is the same as the preceding, but applies to other 
objects. 

k. JYTonstrosities of the same kind are hereditary in seme families. 
This does not cease even by marriages with other families, although 
it sometimes disappears for several generations. The best known 
examples of this are those families with supernumerary fingers. But 
the hare-lip, fissure of the palate, hypospadias, &c, are equally heredi- 
tary. Sometimes a tendency to produce anomalies is transmitted 
rather than an anomaly, although usually the species of aberration is 
then the same. The predisposition does not often extend except to one 
generation ; nevertheless, we may ask if cases of this kind ' have been 
well observed, and if, when such a tendency is developed in one gene- 
ration, it is not transmitted at least to the following generations, as 
certain diseases are developed sometimes under favorable circumstances 
and have now become contagious. 

/. The influence of sex. We may state as a principle that anoma- 
lies are more common in the female. This phenomenon seems to us 
to depend upon the eighth law, since the organization of the female 
results from the development being arrested at an inferior degree. 
Hence it follows also that deviations of formation absolutely opposite 
in their nature are more common in the female than in the male. Ne- 
vertheless certain organs may be exceptions to this rule. Thus, several 



70 GENERAL ANAT0M7. 

anomalies of' the heart(l) and of the bladder(2) are found more fre- 
quently in the male than in the female. 

m. Most deviations of formation are analogous to what is seen in ani- 
mals. The organs of man do not present a single anomaly which is 
not similar to what is seen in animals. A whole book might be writ- 
ten on this subject, and exact observation would multiply to infinity 
the facts we could now mention in favor of this law. It is founded on 
another law, that the human fetus while developing passes through 
several formations, and that those monstrosities which are formed essen- 
tially by the development being arrested in one or another of these for- 
mations, are the most common because they were normal in the first pe- 
riods of its existence. Nevertheless we trace a resemblance with the or- 
ganization of animals in certain anomalies which have never been nor- 
mal, such as the inversion of the least symmetrical organs, and most of 
the varieties of the vessels. This law then can be expressed in general 
terms as follows : All the organisms have one primitive fundamental 
type : hence one may be transformed into another. (3) 

n. The spontaneous appearance of similar 'phenomena during life, 
which do not result from the effect of an external lesion. The alterations 
of texture and all new formations are usually developed spontaneously. 
Why, then, is it not probable, after this, and setting aside too the argu- 
ments hitherto adduced, that, by a stronger reason, congenital mon- 
strosities are original, and do not depend on external influences ? But 
it is a peculiar anomaly which favors this opinion. In several animals, 
especially in the class of birds, the female habits and female desires 
are so effaced by age, that, although the genital organs remain the 
same, yet in these particulars the bird belongs to the male sex. It is 
true that at first sight these phenomena appear to oppose the doctrine 
of original monstrosities, as they show the possibility of a total change ; 
but in truth they favor it, as they combat the opinion which ascribes 
these monstrosities to the influence of mechanical causes. To us it does 
not seem very unlikely that some parts originally well formed in the 
first periods of life should afterwards assume of themselves an abnormal 
form ; that, for instance, some parts at first single should afterwards be- 
come double, instead of merely acquiring an abnormal volume, since 
the inferior organisms, which the fetus so much resembles, have the 
power, not merely of enlarging, but of increasing the number of their 

(1) Schiller, De morbo cmruleo, Muhldorf, 1810, p. 29. 

(2) See Duncan's paper On the malformation of the urinary organs in the Edin. 
Med. and Surg. Jour., vol. i. p. 132. 

(3) This law has been perfectly developed by J. F. St. Hilaire, who has endeavored 
to demonstrate that the organization of vertebraled animals may be referred to a 
uniform type, i. e. that the materials ol all these are the same ; but they vary in size 
forms, and uses, and form the organization according to the wants of the animal and 
the medium it inhabits. Although their forms and size change, their connections 
always remain the same, their relations are invariable. The same materials being 
given, and animated by a sum of life nearly uniform in each class, a greater de- 
velopment of one cannot take place unless one or more of the parts adjacent suffer 
Such are the principles of the truly philosophical theory which J. F. St. Hilaire Ion' 
•ince brought forward (Philosophic anatomique, 1818) as the Theory of analogies. " 

y. t. 



GENERAL LAWS OF FORMATION. 71 

parts, under the same circumstances which in the superior animals 
are at most attended only with an increase of volume. 

§ 39. Thus almost all the congenital deviations from the normal 
form are primitive, or at least do not result from mechanical causes.(l) 
The classification most convenient for their study is that which views 
them in their essence. In fact it is not impossible that the formative 
power when producing them differs only in degree from its normal 
state ; and this proposition, although at present unproved, is not at 
least unlikely. Monsters may then be classed according as they are 
anomalous in quantity or in quality. The first class comprehends, 1st, 
monsters by defect, (monstra per defectum,) their essence is a want of 
energy(2) ; 2d, monsters by excess, {monstra per excessum.) which are 
characterized by an excess of formative power.(3) The second are 
divided into those which depend upon the union of the characters of 
both sexes in the same individual, or the hermaphrodites, (monstra an- 
drogyna)(A), and 2dly, those which cannot be referred to any of the 
preceding classes, (monstra per fabricam alienam.) 

To the first class of the first section are referred the defect, smallness, 
and too long continuance in the forms or proportions of early youth ; 
to the second, the plurality, excessive volume, and too rapid develop- 
ment. The objects of the second section are expressed generally by 
the definition itself. As to the classes of the first, it appears that, 
besides the first two conditions, which are common to all the organs, 
the same kind of anomaly presents as many differences in each organ 
as naturally occur in its normal form and development. Besides the 
differences relative to the frequency of the anomalies, which we have 
before mentioned, we may remark that we find more deviations in 
formation in those organs which while developing pass through the 
greatest variety of forms ; because this circumstance increases the 
number of temporary forms in which they can stop. Perhaps there are 
organs peculiarly predisposed to one or another class of deviations of 
formation ; this would certainly seem to be the case : thus, for instance, 
the abnormal multiplication is observed particularly in the limbs, but 
seldom in the internal organs or in the trunk. We may establish then, 
as a general law, that an increase of the formative power is directed 
rather to the surface, and diminution inwardly. Nevertheless there is 

(1) J. F. St. Hilaire has settled this important proposition also, (Des monstru- 
osites humaines, Paris, 1822.) Monsters have given new support to his doctrine of 
the unity of composition in vertebrated animals. In fact he has observed that these 
anomalies are usuallymarkedbythe excess or deficiency of only one of the parts which 
form the being in its proper state, but that the parts themselves are often equal in 
number, and their relations are always the same. Although these observations have 
been confined to monstrosities of the head, they are sufficient for us to conclude, by 
induction, that all others enter into this common law, and that their origin is truly 
dynamic and vital. F. T. 

(2) We have given the complete history of these deformities in our Handbuch der 
pathologischen Anatom.it. 

(3) The general laws and particular conditions of these anomalies have been men- 
tioned in our Commentarius de duplicitate monstrosa, Halle, 1815. 

(4) Besides several treatises on hermaphrodites, some of which are excellent, as 
those of Ackermann and Burdach, consult the second volume of our Handbuch der 
pathologischen Anatomic. 



72 GENERAL ANATOMY. 

only a difference in degree, as nothing is rarer than monsters from 
defect of the external parts. 

§40. Alterations of texture extend to all qualities connected with 
the intimate composition, that is to say, principally, 1, to the color ; 2, 
the density ; 3, the number and the composition, of the particles which 
contributed form the whole part ; and finally to the chemical composi- 
tion. 

Alterations in texture, considered generally, consist essentially in the 
formation of a tissue different either in one or in all parts from the 
normal tissue. 

1. The abnormal colors are very often accidental and foreign to 
the tissue which presents them. This takes place when, as in jaun- 
dice, cyanopathia, &c, the color of this tissue arises solely from the 
morbid state of other organs, or when it is not situated in the tissue, 
but in the fluids it contains ; it then disappears as soon as the disease 
which caused it is cured. On the contrary,, the color is rarely or even 
never normal when the tissue varies from the rule in another relation : 
in this case it is darker, brighter, or entirely different. Generally it 
becomes more clear when the morbid alteration is not caused essentially 
by an excessive development of the vessels. 

2. The density is sometimes greater and sometimes less. In the 
first case, the organs are hard and firm, in the second, loose, soft, brit- 
tle, and fragile. 

3. Usually the morbid tissue is less distinct and more uniform ; the 
number of vessels is often increased, and often also diminished, &c. 

4. The chemical composition also varies much. Here applies all that 
has been said above with regard to its intimate texture. 

We should observe in general that the texture of the organs changes 
in two different ways. Sometimes an organ whose conformation is 
regular is partially or wholly changed into an abnormal tissue. Some- 
times a new and anomalous tissue is developed near it, entirely differ- 
ent from the old tissue, which disappears as the former increases. 
Nevertheless this difference is only apparent, for even in the latter case 
the new tissue is unlike that whose place it supplied, and is only the 
change of another, ordinarily of the mucous tissue, which has assumed 
an abnormal state. 

The most general condition of the alterations of texture, and the 
most general cause of their production, is inflammation, which may be 
denned a state in which the blood flows in greater abundance towards 
a part of the economy, and attempts a new formation. 

Even the alterations of texture are either the repetitions of a tissue 
which already exists in the normal state, or formations entirely abnor- 
mal, which do not exist in the regular state. 

All the parts are not anomalously produced, nevertheless this is the 
case with almost all, and especially the most simple. Thus we see the 
cellular tissue abnormally produced, which then contains fluids of a 
different nature ; the tissue of the bones, and even enamel, that of the 
cartilages, the fibro-cartilages, the fibrous tissue, the skin, and several 



GENERAL LAWS OF FORMATION. 73 

parts of the epidermoid tissue, especially the horny parts and the hairs : 
the serous texture, which, like the cellular, contains different fluids, the 
synovial tissue and the mucous tissue. 

As the vessels and nerves enter more or less evidently into the for- 
mation of several of these tissues, we may say they are reproduced 
in an abnormal manner, whether they do or do not arise from vessels 
and nerves previously existing. 

The muscular and glandular tissues are those only which appear 
not to be formed anew. 

These repetitions of the normal formations take place principally 
in two different circumstances : sometimes to repair a loss of substance, 
and consequently at the place where the organ usually exists ; some- 
times accidentally, and in other places. This difference is merely ac- 
cidental : the proof is, that those parts which are easily and perfectly 
reproduced after having been destroyed, or those which grow more 
than once in the 'normal state, are those also which are most completely 
and frequently developed as anomalies in other parts of the economy. 
Here are included the mucous tissue, the bones, the teeth, the hair, 
and especially the epidermoid tissue. 

On the contrary, the muscular and the glandular tissues are never 
reproduced. 

The most essential characters of the new formations of this kind, 
resemble those of the parts of which they are repetitions : their tex- 
ture and chemical composition are the same : they pass through the 
same periods of development, and exercise no injurious influence on the 
health and life unless from their mechanical effects, or because they di- 
vert the formative power from other organs. The accidental differences 
found in parts which are produced abnormally, are a less perfect form, 
a chemical composition which is often not exactly the same, while their 
duration is shorter. 

It is difficult to class the abnormal formations which are entirely new, 
because they differ only by insensible shades. Generally they have 
this in common, that at first, they are more solid than the organs in 
which they are developed, or which are changed to them, which de- 
stroys them and those organs ; and that in all those and particularly 
during the latter periods of their existence, they have a marked pro- 
pensity to pervade the whole organism. 

§ 41. XI. The organic form every where presents traces of a forma- 
tion in accordance with the purpose to be attained. It is impossible 
not to perceive that an intellectual power, whatever may be its rela- 
tions to matter, has governed the formation of the organized bodies. 
This is especially confirmed by those mechanical arrangements which 
we find in a multitude of places, and by the greater protection given to 
the organs essential to life. Among the phenomena of the first class, we 
shall mention the valves established in those vessels which have no im- 
mediate power of impulse, as the veins and the lymphatics, and the multi- 
plicity of these valves, either at those points where the friction is greatest, 
as in the small veins and in the lymphatic vessels generally, or in those 

Vol. I. 10 



74 GE.NEKA1. ANATOMY. 

where there is no mechanical impulse, as in the lymphatic system- On 
the contrary, there are no valves in those veins where the different trunks 
anastomose together. In other parts of the vascular system, also, as 
at the base of the aorta and pulmonary artery, between the ventricles 
and auricles, we find valves which oppose the reflux of the blood. A 
similar arrangement exists also when it is required to separate parts ol 
the same cavity in which different functions are executed : for instance, 
at the union of the stomach with the small intestine, and of the latter 
with the large intestine, &c. 

As to the phenomena of the second kind, we see that the organs 
most essential to life, as the brain, spinal marrow, and lungs, are wholly 
or partially inclosed in large cavities, the skull, vertebral column, and 
the thorax, which are also particularly remarkable, on account of their 
circular form. So, likewise, the veins are situated less deeply than the 
arteries. 

The duplication of most of the organs deserves also to be regarded in 
this point of view, since it allows the continuance of the function, even 
when an organ, or a portion of it, is destroyed. Sometimes the remain- 
ing organ increases in size, as happens, for instance, in the kidneys ; 
while, sometimes, the sound portion redoubles its activity, as in the 
brain, lungs, &c, although in fact one half can never be perfectly re- 
placed by the other. 

The texture and external form of all the organs seem to harmonize 
with the final end of the organism, since most anomalies soon suspend 
its functions. 

§ 42. Each organ has its peculiar functions. Nevertheless, there 
are certain conditions, in respect to which the functions of some organs 
agree together better than in regard to certain others. On this is 
founded the classification of the functions. The first, and most gene- 
ral division is that which divides the organic actions into functions 
which are related with consciousness, with the spiritual existence, which 
connect mind and the external world, the animal functions properly so 
called, and into those which immediately concern the material existence, 
the preservation of the substance, which are accomplished without con- 
sciousness, the vegetative functions. These functions unite and constitute, 
the first, the animal life, the second, the vegetative, organic, or automatic 
life, a division to which Buffon,(l) Grimaud,(2) and Bichat(3) have 
called the attention of physiologists. The latter has assigned to the 
two lives, and among other things to the forms of their organs, peculiar 
characters which have been adopted by modern writers,(4) and are re- 
duced to the following : * 

1. The organs of animal life are symmetrical, those of organic life 
are unsymmetrical. To the first class are referred, 1, the brain and 
spinal marrow, with their nerves and appendages, or the nervous sys- 

(1) Histoire des Animaux, Paris, 1709, vol. ii. cli. 1. 

(2) Memoire sur Nutrition, St. Petersburg. 1789, p. 3. 

(3) Bichat, On Life and Death. 

(4) Sprengel, List. Med. vol. i. p. 197, 199. 



GENERAL LAWS OF FORMATION. 75 

tern of animal life ; 2, the muscular system ; 3, the osseous system ; 
and 4, the organs of voice. The second comprises, 1, the vascular 
system ; 2, the great sympathetic nerve ; 3, the digestive apparatus ; 
4, the respiratory apparatus ; and 5, the urinary apparatus. This dif- 
ference, as respects symmetry, is seen even in the anomalies, which 
appear on both sides at once in the first class, and exist on one only in 
the second. 

Lately, some have wished to establish between the different systems 
of the animal life, differences founded upon the greater or less perfection 
of the symmetry, and still more recently, it is pretended that the os- 
seous system exceeds all others in this respect.(l) 

2. The organs of animal life are formed in a type more constant than 
those of vegetative life : hence anomalies are as frequent in the latter 
as they are rare in the former. 

3. The influence behveen the form and the activity of the organs in the 
two lives, is entirely different. An anomaly in the form of an organ of 
animal life, instantly deranges its functions, while the most considerable 
aberrations in that of an organ of organic life are not attended with bad 
consequences. The normal condition of both halves of the organs of 
animal life is especially necessary in order to the regular performance 
of their functions ; for every derangement in one of them is followed 
immediately by an interruption in the whole function. On the con- 
trary, one part of an organ of vegetative life may be diseased without 
incommoding the function, if the other portion supplies its place. 
And again the symmetry is such, that one half of an organ of animal 
life may be diseased, while the other remains in a state of perfect health; 
while the disease of one half of an organ of vegetative life deranges 
the functions of all. 

Although these characters are true to a certain extent, yet they are 
too general. It is true, and the remark has already been made, (§23,) 
that the organs of animal life are disposed more symmetrically and more 
constantly than those of vegetative life. But this difference is only in 
degree, and is not a direct contrast. Neither are the organs of animal 
life entirely symmetrical, and when we consider what has been before 
stated, the symmetry of the organs of organic life seems still more per- 
fect. This difference, too, has no general value, since comparative ana- 
tomy demonstrates that it is not observed in the great majority of ani- 
mals, for, in most of them, the organs of organic life are not less sym- 
metrical than those of animal life, although Bichat seems to admit the 
contrary. Besides, even in man, the genital system is disposed with as 
much symmetry as any system of animal life, while that belongs only 
to vegetative life. It is true that Bichat separates it from these organs, 
saying that it does not relate to the individual : but he is mistaken, 
since the essence of the functions fulfilled by this system, corresponds 
perfectly to that of the other organs of vegetative life. It is not true 
that the anomalies of the organs of animal life exist on both sides at 
once, and that those of organic life are found on one side only. We 

(1) Bartels, Physiologic, Freyburg', 18(19, p. 21, 



76 CENEUAI. ANATOMY. 

have almost always found varieties in the distribution of the vessels of 
the upper extremities, of the kidneys, &c, on both sides at the same 
time, while anomalies of the muscles and of the bones are frequently 
found only on one side. That the osseous system is more symmetrical 
than the other systems of animal life, is also false. The same system de- 
monstrates, also, the too great generality of the proposition which states 
that the type of the formation is more constant in the organs of animal, 
than in those of vegetative life, since we meet varieties of form in the 
bones, as often at least, as in the vascular system. Finally, the greater 
frequency of anomalies in the organs of vegetative life depends on the 
greater number of stages through which they pass. "When these 
stages are numerous, as in the osseous system, and especially in some 
of its parts, deviations from the normal form are also very frequent. 

The third proposition, especially, is too general. All the truth it con- 
tains, is, that deviations in the form of organs affect their functions, if 
these functions depend in any measure on mechanical arrangement. 
It is of no consequence whether the kidneys are lobed or not, united or 
separated ; whether the stomach or heart is on the right or the left side, 
&c; but when the kidneys are too small, or when one kidney is deficient, 
when the ureters are obliterated, when the stomach is contracted in its 
centre, when the valves of the heart are deficient or adhere, when there 
is only one ventricle instead of two, when the aorta arises from both of 
these cavities at once, &c, the derangements are certainly more impor- 
tant than when the brain is oblique, when one side of the skull possesses 
more wormian bones than usual, or when a muscle is attached to an 
unusual number of ribs. 

This pretended difference is then without foundation, and both for 
this reason, and because that duplication has been confounded with 
symmetry, the propositions mentioned by Bichat in his third law ab- 
solutely contradict each other. The normal arrangement of two parts 
of an organ of animal life is necessary only when, by their structure 
and relations with external objects, they form a single organ, and when 
their external form is connected with their functions, as happens, for in- 
stance, in the organs of the senses. When this is not the case, a devia- 
tion in formation of one of the portions has no bad effect, because it is 
replaced by that which is not mal- formed. The disease of one half of 
an organ of vegetative life does not always affect the function of the 
whole. When one kidney is diseased, the other enlarges. It is true 
that the disease in a part of an organ of vegetative life affects the func- 
tion of the rest, but only when the different organs are parts of one 
whole ; thus, a disease of the liver affects digestion, because the liver 
forms part of the digestive apparatus. 

§ 43. So far in regard to the general conditions of the human form : 
before we pass to the general description of the individual organic sys- 
tems, let us attend to the general conditions of the chemical composition 
and the actions of the human organism. 

§ 44. The human body, like all other organized bodies, is composed 
of proximate and remote chemical elements, even as it contains proxi- 
mate ani remote elements of form. 



GENERAL LAWS OF FORMATION. 77 

Among the remote elements, there is no one which is peculiar to it ; 
all are met with in the general organism. It contains, on the contrary, 
some of the elements found in nature, but not all. 

The union of several remote elements produces the immediate elements 
which belong particularly to organisms. We find especially oxygen, 
hydrogen, carbon, azote, and phosphorus, in almost all the imme- 
diate elements. The predominance of one or another of these prin- 
ciples distinguishes the materials from each other, as that of azote and 
phosphorus characterizes the chemical composition of animals, and 
consequently of man. Some of the immediate elements are more ge- 
nerally diffused, and concur to form more of the solids and fluids than 
others which are found only in certain parts. 

Those which exist most generally are albumen, fibrin, gelatin, a 
peculiar substance, mucus, which resembles gelatin very much, and 
was long confounded with it, fat, and several salts, which also occur in 
other than organized bodies. Fibrin, gelatin, and albumen, are only 
modifications of one and the same substance ; they may be converted 
into each other by art : so too the most varied forms may be finally 
reduced to a certain number of simpler terms (§5). 

The immediate elements which every where exist are, with the 
exception of gelatin,(l) contained in the common nutritive fluid, the 
blood. The blood is composed of globules (cruor, globuli) and of a 
coagulable fluid : the latter consists of serum and fibrin, the primitive 
elements of form. 

The fat is a substance generally diffused, which does not enter 
into the composition of organs, but only envelopes them. 

The immediate principles which are found only in certain parts are 
acids and salts, or other compounds, which appear principally in the 
secreted fluids, to which they impart their peculiar characters. 

These immediate principles concur in different proportions to form 
the different organs and the different fluids ; and even viewed che- 
mically, they may be considered as the proximate elements of the 
organism. 

All the organic combinations, with a very few exceptions, take place 
contrary to the usual laws of affinity ; hence sooner or later after 
death they form other compounds, which obey the laws of affinity, 
and which differ from those above-mentioned, principally because they 
contain fewer elements, because they are more simple. 

Although the solids and fluids differ from each other by the excess 
of an immediate principle more or less properly belonging to them, and 
this peculiarity depends in its turn on the predominance of an imme- 
diate principle, still they may all be divided more or less easily into two 
classes, opposite to each other in this respect, that there is an excess of 
free acid in the first, and of free alkali in the second : a contrast which 
is also developed by electricity in the heterogeneous fluids. (2) 

(1) Bostock, in Med. Chirurg. Trans. London, 1809, vol. i.— Marcet, ibid. vol. ii. 
— Berzelius, ibid. vol. iii. 

(2) Besides the general works of Thomson and Thenard, we may consult on ani- 
mal chemistry J. J. Berzelius, Focrelaesningar i Djurkemien, Stockholm, 1802-6, 



78 GENERAL ANATOMY 

§ 45. The organisms possess dead and living forces, which differ 
from each other inasmuch as the latter do not belong to them except 
for a certain period called life, during which only they may be consi- 
dered as organisms enjoying a separate existence. Nevertheless these 
dead forces themselves differ very much during life and after death, 
for they depend on the form and chemical composition of the parts : so 
that the change death brings in this form and composition ought neces- 
sarily to produce other phenomena. 

The living forces of the organisms may be referred to three, accord- 
ing to the different phenomena of action presented : 1, productiveness, 
(productivitas) ; 2, motivity, (motilitas) ; 3, sensibility., {sensilitas). 

All the phenomena arising from these forces can also be reduced to 
two classes, according to the principle which forms the basis : these 
are the material and the intellectual : for we observe that the substance 
changes in the phenomena of formation and motion ; but this is not 
seen in those of sensation. 

The phenomena of formation essentially consist in the production of 
a peculiar substance,formed at the expense of another which is unlike it. 
The formative power shows itself in preserving the normal state, or in 
bringing to it the abnormal state. If this abnormal state be so changed 
to the normal state that a new part forms in the place of that which has 
been destroyed, the phenomenon is called regeneration or reproduction 
(regeneratio, reproductio) ; so too the preservation of the normal state 
of the species by the formation of a new creature is called generation 
(generatio). The substance which produces all these new formations 
is the common nutritious fluid, the blood, which is itself formed from 
heterogeneous substances, in accordance with the same laws by which 
all organic products are derived from it. The quantity of nutritious 
fluid increases then in a local or general manner, in order that each 
new formation may take place : and this state may be generically 
termed inflammation. 

The essence of the phenomena of motion is an alternate change in the 
degrees of cohesion and form, which increases the volume in one direction 
at the expense of the same volume in another direction. When a part 
endowed with this power contracts and shortens, it swells, and becomes 
thicker ; whei> it lengthens, it seems more and more thin. But in the 
first of these two states it is also much harder than in the second ; 
either from this circumstance, or because the first state is the imme- 
diate result of an irritation acting on the part, it is called the active 
state of the organ susceptible of motion. We are certain that, although 
the volume and the mass are the same in the two cases, nevertheless 
the nature of the two states is entirely different, even when the che- 
mical composition of the part should not be modified, and the difference 
should consist only in a change of cohesion. 

2 vols.— Id., Ucbcrbliclc uber die Zusammcnsetzung dcr thierischen Fliissigkeitcn, 
Nuremburg-, 1814.— Id., Vebersicht der Fortschrit'te und des gegenwaertigen Zus- 
tandes der thierischen Chemie, Nuremburg, 1815.— J. F. John, Chemische Tabellen 
des Thierreichs, Berlin, 1814. 



GENERAL LAWS OF FORMATION. 79 

This vital motivity differs much from similar dead forces, particularly 
from that of elasticity, although it is somewhat analogous to them. 
Neither should we confound it with the extensibility and the contrac- 
tility of tissue admitted by Bichat, who represents them as principles of 
peculiar phenomena, which are either phenomena of formation or 
merely those of elasticity. 

The phenomena of motion have also been classed either from the 
manner in which this motion is manifested, or from the relation between 
it and the cause on which it depends. Thus they are distinguished 
into voluntary and involuntary motions, or into animal, which are con- 
sidered as belonging to animals only, and into organic. The latter 
have also been divided into sensible and insensible. But if the first 
classification, founded on the relation of the phenomena to their remote 
causes, be correct, the second is not, since the insensible organic mo- 
tivity depends only on the phenomena which become active probably 
in another manner. 

Sensibility is the power of receiving and of propagating impressions. 
It belongs to the nervous system, which should be considered as the 
organ of the internal principle, or organ of the soul, since it is in one of 
those parts that the spiritual principle experiences, from the impressions 
received by its periphery, the spontaneous changes afterwards trans- 
mitted to other organs by the conducting portion of the system. 

As all the nerves do not propagate the impressions they receive 
even to that part of the nervous system in which the changes relative* 
to the intellectual phenomena take place, or which immediately cause* 
them ; and again as all the intellectual changes are not transmitted to 
the same organs, the sensibility may be distinguished into animal and 
organic ; and although this difference relates only to the nerves, we 
may extend it to the organs themselves : so that some are organs of 
animal and others organs of organic sensibility. Nevertheless, we 
would ask, if to establish this distinction too much latitude be not given 
to the idea of sensibility, or if that be not wrongly confounded with that 
of susceptibility in general. Then . the animal sensibility alone would 
be called sensibility, and those parts destitute of it would be called 
insensible. The phenomena alledged in support of the hypothesis of 
sensible or insensible organic sensibility, do not prove its reality ; even 
as, on the other hand, those which they assure us demonstrate the 
presence of a pretended sensibility purely organic in certain parts, are 
not sufficient to justify the admission of this hypothesis. 



GENERAL ANATOMY. 



PART II. 



DESCRIPTION OF THE INDIVIDUAL ORGANIC SYSTEMS. 

§ 46. We have already stated, (§15,) that the different systems 
composing the organism, are divided into general and particular. The 
general systems, the mucous, the vascular, and the nervous systems, exist 
in all parts of the economy, and everywhere unite to constitute the body; 
and form, more or less perceptibly, the basis of all the other systems. 
They differ, however, in their extent : that of the nervous system is much 
less than that of the vascular, and the latter cannot be demonstrated 
in many parts where the mucous tissue is evident. The mucous tissue, 
then, is the most general, and, in fact, is the matrix of all the organs. 
It also is the first to appear. We ought, then, to mention it first. 



SECTION I. 

OF THE MUCOUS SYSTEM. 

§ 47. The mucous system,(\) or cellular tissue, (tela seu textusmucosus, 
cellulosus, cribrosus,) is one of the two elementary forms to which, in 
ultimate analysis, the whole organic formation may be referred. It is 
the coagulable fluid coagulated. . It is generally described(2) as an 

(1) D. C. Schobinger, De telee celluloses in fabrica, corporis humani dignitate, 
Goettingen, 1748. — Thierry, E. in celluloso textufrcquentius morbi ct morborum mu- 
tationes, Paris, 1749, 1757,1788. — Hunter, Remarks on the cellular membrane and 
some of its diseases, in the London Med. Obser. and Inquiries, vol. ii. p. 26. — Th. 
Bordeu, Recherch.es surle tissu muqueux on cellulaire, Paris, 1767. — J. Abadie, Diss, 
de corpore cribroso Hippocratis, seu de textu mucoso Bordevii, Montpelier, 1774. — 
C. F.Wolff, De tela, quam dicunt cellulosa, obser vationes: in the Nov. Comment. Pctro- 
pol., vol. vi. vii. and viii. — Detten, Beytrag zu dcr Lchre von der Verrichtung des 
2Zellgewebes. Munster, 1800. — Luca;, Anatomisch-physiologLsche Bemerkungen uber 
den Zellstoff: in the Annalen der Wetterauer Gesellschqft fur die Naturkunde,\o\. ii., 
1810. — G. R. Treviranus, Uebcr die organischen Elcmcnte des thierischen Kocrpers : 
in Vermischte Schriften, vol. i. 1816, p. 124. — Felici, Cenni di una nuova idea sulla 
natura del tessuto cellulare, Pavia, 1817. — Heusinger, System der Histologic, Eise- 
nach, 1823, Part II. p. 121. 

(2) This is the view taken by Haller, Bergen, Schobinger, and Thierry. This opi- 
nion was adopted by Bichat, and recently by Beclard and Blainville, and is now ge- 
nerally received in England, France, and Italy. Bordeu's opinion, which Meckel 
follows, has been defended in Germany by Wolff, Autenrcth, Prochaska, Blumen- 
bach, Rudolphi, Treviranus, and Heusinger. p. T. 



OF THE MUCOUS SYSTEM, OR CELLULAR TISSUE. 81 

assemblage of numerous layers, and of soft and white fibrils, which, 
varying constantly in their arrangement, produce cellules of different 
sizes and forms. All these cellules communicate, so that the whole 
tissue forms but a single cavity which is infinitely subdivided, from 
which circumstance its most common name, cellulttr, is derived. But 
when closely examined, it is perceived that this assertion is at least too 
general, and that the mucous tissue is a cohesive, homogeneous, viscous, 
shapeless, and but slightly solid substance. It appears thus in the in- 
ferior animals, and in the commencement of all formations. In fact, 
we see at first only this homogeneous semi-fluid mass, in which globules 
afterwards appear, and concur to form the whole organism. There 
exists primitively between it and these globules, and afterwards between 
it and the organs, the same relation as between the shapeless portion of 
the fluids, and the globules which swim in them. 

We may be convinced of the exactness of this representation at all 
periods of fife. Neither layers, fibres, nor cells, are perceptible to the 
naked eye, even when aided by a microscope, and we see only the sub- 
stance spoken of by us, without the least opening. This substance ap- 
pears to be composed of fibres and layers only because its viscidity 
causes it to assume that form when it is extended, and with or without 
a microscope these layers and fibres may -be seen to form under the 
eyes of the observer. When, for instance, we separate two muscles or 
muscular fasciculi, the homogeneous substance between them becomes 
at first uneven, and appears filled with channels, without always losing 
its cohesion. But if this traction be continued, or if more force be used, 
it tears and produces filaments' or small cylindrical columns, which be- 
come very long if the extension be sustained. If we cease to extend it, 
so that the space occupied by the substance is diminished, the filaments 
first shorten and finally unite anew in a coherent mass. 

When the mucous tissue is extended, air sometimes accidentally pe- 
netrates it and produces vesicles of different sizes and figures. But this 
air escapes when the tension ceases and the tissue then assumes its pri- 
mitive form. The cellules which arise in this manner are not always the 
same, for if these parts be again separated the air penetrates anew, 
but the cells now formed are very different from the first both in size and 
form. When these cells remain by continued extensions, the air is confined 
only by the contraction of the mucous tissue at the moment when the 
traction ceases, so that, when renewed, cells of the same form are natu- 
rally produced. When air penetrates into the mucous tissue, it can be 
pushed in every direction; we can divide or reunite the vesicles to 
which it gives rise, and thus vary their form to infinity. 

The facts which Bichat(l) regarded as proving that the mucous tis- 
sue is an assemblage of filaments and laminae, demonstrate only that, 
when properly considered, this substance can assume this form, whenever 
the circumstances are favorable. Thus, for instance, it is pretended 
that the distension of a part of the mucous tissue of the scrotum would 

(1) Bichat's Gen. Anat. vol. i. p. 114. 
Vol. I. 11 



82 GENERAL ANATOMT. 

demonstrate its lamellar and fibrous structure, because it then appears 
as a transparent membranous layer, presenting many irregular filaments, 
which are seen when more force is used, as the spaces between them 
are then enlarged. But this experiment only proves that whenever 
the homogeneous mucous tissue is distended, it can assume the lamel- 
lar and the fibrous form. 

Accordingly, then, as we simply extend the part, or at the same time 
inflate it with air, and as the substance is more or less viscid, we obtain 
in the same part either vesicles of different sizes, or filaments, or, finally, 
both vesicles and filaments, at the same time we then see simple 
meshes, or true permanent cells. 

Nor does the cellular structure obtained by congelation prove that 
this arrangement is original. As the mucous tissue is always filled 
with liquids, the interstices they occupy must become permanent by 
freezing. 

These pretended fibres have also been called absorbent or exhalent 
vessels, because they are discovered only in those portions of the mu- 
cous tissue which have been formed into membranes by extension, and 
have not been observed in those parts which have a cellular form from 
the introduction of the air. But it is easily perceived that this differ- 
ence also depends on the process employed ; for traction ought neces- 
sarily -to produce fibres ; while distension by air, which acts in every 
direction at once, gives rise only to laminae and vesicles. 

The color of this semi-transparent substance is grayish. The white 
tint commonly attributed to it does not belong to it, but results only 
from the reflection of light from an infinite number of surfaces when 
laminae and filaments have been artificially formed. The term mucous 
tissue already adopted by Bordeu, is then more exact than that of 
cellular tissue which is generally used. 

§ 48. All the phenomena presented by the mucous tissue are ex- 
plained with as much, and even with more facility, by the hypothesis of 
this structure, than of that of the formation usually attributed to it. 

The most remarkable property of this tissue is its penetrability or 
permeability. Foreign substances which are accidentally introduced, 
or which are abnormal only from their great abundance, are frequently 
seen in parts the most distant from where they entered ; or when they 
form a coherent mass, they sometimes extend through the whole 
tissue and sometimes are expelled only by one opening. ' 

Here we may mention, 

1st, The migrations of those firm solid bodies which have penetrated 
into the organism. Thus, pins which have been introduced into the 
stomach proceed to the fingers, the toes, or the other regions of the sur- 
face of the body, as the loins, sides, &c. Often too they are carried 
from the surface into other parts, and move from the arm towards the 
chest — from the hand towards the upper part of the arm, &c. 

2d. The facility with which general emphysema is produced by 
blowing air into any portion of the body, and the ease with which the 



OF THE MUCOUS SYSTEM, OR CELLULAR TISSUE. 83 

air passes out from a single opening.(l) Air, if introduced under the 
skin penetrates, not only below the cutaneous organ and the parts 
covered by it in the whole body, but also within the. interstices of the 
muscles and into the substance of all the viscera. The same thing hap- 
pens after wounds of the lungs ; the air which is constantly renewed 
by respiration, passes, first, through all the branches of the bronchial 
system in its mucous tissue, and from thence into every part, so that 
the body often resembles a large bladder distended by air. 

3d. The ease with which collections of pus point at a distance. The 
pus of abscesses developed in the chest burrows a passage to the feet 
through the mucous tissue which fills the interstices of the organs. 
Urine, which filters through a wound in the bladder, penetrates the 
cellular tissue of the abdomen, and even of the chest. The blood from 
a wounded artery spreads itself through the cellular tissue of an entire 
limb, &c. 

4th. In a general anasarca all the serum sometimes escapes by an 
accidental or artificial opening, if the nature of the fluid will permit. 

These phenomena are commonly attributed to the continuous com- 
munication of the cellules with each other ; but they may be explained 
as well by the softness and semi-fluidity of a cohesive substance. All 
these unusual passages are but temporary, and it is evident that many 
of the above mentioned phenomena, as the migrations of foreign bodies, 
and of collections of pus, favor the hypothesis of the cellular structure 
of the tissue less than that of its mucous structure, for it is not pro- 
bable that these bodies would follow the direction of the cellules. They 
burrow, removing, destroying, and separating, purely mechanically, 
the mucous tissue before them : in the former case the tissue is repro- 
duced, or collapses when they have passed ; in the latter case the dis- 
ease, which at first was slightly developed, is now extended. If we be in- 
correct, how do bodies which have been swallowed descend from one 
cavity to another ? How do pins proceed from the intestinal canal 
into the vessels 1 Why is the mucous tissue altered at all points where 
it contains pus ? None of these phenomena demonstrate a cellular 
structure, and many prove the contrary. 

§ 49. The relations of the mucous tissue with the organs are of 
two kinds ; it forms, or does not form, one of their essential parts. In 
the first place it may be called the internal or special mucous tissue in 
the second, the external, or general mucous tissue. 

The former contributes to form the organs, either alone or combined 
with nerves, vessels, or a peculiar substance which pervades it : the 
second is found between the organs, and fills the intervals between 
them. But at the same time both unite ; for the external mucous tis- 
sue gradually blends with that which properly belongs to the organs. 

(1) We have seen several of these general emphysemas which so commonly follow 
wounds of the lungs, and which sometimes result from the rupture of a cartilaginous 
ring of the trachea. Air penetrates into the mucous tissue very rapidly, but when 
a large opening is made fornt, but little escapes, even when we press around the 
wound. Most probably, then, it is absorbed, rather than expelled. F. T. 



84 GENERAL ANATOMY. 

As the mucous tissue of the organs penetrates all their substance, the 
distinction between the internal and external mucous tissue is not very 
strict, and the whole body is imbedded in mucous tissue. The most 
essential difference between these two tissues relates only to the func- 
tions. The internal mucous tissue contains the different substances 
which form the organs, while the external includes only the fat and se- 
rum, which are necessary for their continual reproduction, and also 
for their constant activity. 

§ 50. The external mucous tissue may, nevertheless, be considered 
as forming, in some measure, a separate system: for in the different 
regions of the body it is connected with the internal mucous tissue less 
intimately than with its own peculiar parts. Setting aside both this 
internal tissue and the organs it assists to form, it represents an unin- 
terrupted system, which is a duplicate of the form of the whole body, 
but which, in certain parts, differs considerably in regard to quantity, 
cohesion, and the nature of the fluids it contains. Besides the general 
connections between all the portions of the mucous tissue there are 
places where those of the principal regions, which correspond with the 
principal regions of the body, pass more particularly and imperceptibly 
from one to the other. Although these details may belong strictly to 
special anatomy, they should be anticipated here, since we must know 
them to acquire a complete idea of the mucous system. 

The mucous tissue exists but in a small quantity within the verte- 
bral column and the skull ; the cavity of the spine contains more than 
the skull, especially between the dura mater and its bones : and there 
also it contains an abundance of fat, which is not found in the cranium. 
This phenomenon is very remarkable, since in several animals, parti- 
cularly in most fishes, a very considerable mass of fat is found within 
the cranium between its parietes and the brain which is small in rela- 
tion to the capacity of the cavity, so that the substance scattered be- 
tween the organs, as nutrition in reserve, exists at least where the 
brain is still very imperfectly developed. 

On the contrary, much mucous tissue exists around the vertebral 
column, and there is always more before than behind, and also around 
the head. 

In the trunk this tissue abounds, not only around the vessels which 
proceed along the vertebral column the aorta and the vena cava, in the 
thoracic and abdominal cavities, in the neck around the carotid arte- 
ries, the jugular veins, the pneumogastric and sympathetic nerves, and 
the esophagus, but it accumulates in great quantities in several parts of 
those regions. On the sides of the neck, at its upper part, it surrounds 
the numerous lymphatic glands and the salivary glands, and below, 
the vessels and nerves of the upper extremities as they emerge from 
the thorax. It abounds in the chest in the twomediastina and around the 
large vessels : and without this cavity, especially at its superior part, it 
exists around the mammary glands, and also between the two pectoral, 
and the serratus magnus, muscles. There is more in the abdomen than 
in the chest, particularly around the kidneys and at the entrance of the 



OF THE MUCOUS SYSTEM, OR CELLULAR TISSUE. 85 

vessels into the abdominal viscera, between the folds of the peritoneum, 
and especially in the mesentery. But in no part is it more abundant 
than in the pelvis, around the rectum, the internal organs of generation 
and the bladder, and it thus favors the great enlargement of the parts 
within this cavity. It accumulates also on the outside of the pelvis and 
principally forward in the external genital organs, the scrotum, and the 
labia pudenda. On the external surface of the skull there is less than in 
the face where large masses exist in the orbits of the eyes, between the 
muscles of the face, in the cheeks, and around the mouth. 

In the limbs its quantity is in a direct ratio with the extent of motion 
in the different regions. It is most abundant in the axilla and in the 
groin ; and there is more in the former than in the latter : less is found 
in the succeeding articulations. There is not so much between the 
muscles of the arm and of the thigh, as between those of the fore arm 
and the leg, and of the hand and the foot. 

The masses of internal and external mucous tissue communicate 
together in the different regions of the body, principally by the open- 
ings of these regions and the spaces between them. These are then 
the points through which abnormal substances pass from one region 
to another. 

The mucous tissue of the cavity of the spine, communicates with 
that which covers the spinal column externally, principally by the in- 
tervertebral foramina ; and the mucous tissue of the cavity of the 
skull is connected with that of the exterior of the skull and of the 
face by openings for the passage of the nerves, as also by the great 
and small emissary veins. That of the face is continuous, particu- 
larly on the sides of the lower jaw, with the mucous tissue of the 
neck : this mucous tissue of the neck unites with that of the thoracic 
cavity, in the place where the vessels and nerves of the arm emerge 
from the thorax ; this proceeds to the abdomen along the large vessels, 
especially the aorta, and along the esophagus also, passing through 
the openings in the diaphragm designed for the passage of these ca- 
nals, and gliding at the same time through the smaller perforations in 
this muscle. The mucous tissue of the abdomen communicates with 
that of the organs of the pelvis by the inguinal ring, the crural arch, 
the sciatic notch, the foramen ovale, and the lower cavity of the pelvis. 

§ 51. The mucous tissue immediately connected with the organs, for 
which we cannot find a better term than special, also divides into two 
parts : the external serves to envelope each organ, continues itself im- 
perceptibly with the general mucous tissue, and forms the transition 
from the general to the special mucous tissue : the internal, on the 
contrary, concurs with the materials coming from the other systems to 
form the organs. 

The external portion of the special mucous tissue forms around each 
organ a layer which separates it from the rest. We may say, then, 
with Bordeu, that this tissue represents a kind of atmosphere. This 
separation, as a layer, is produced, first, by the peculiar life of the mu- 
cous tissue ; secondly, by the fat and serum with which it is filled. 



86 GENERAL ANATOMY. 

The most important organs, then, are generally imbedded in the 
largest masses of this tissue, whenever they are not insulated by other 
modes ; although, in certain cases, this result is produced by the two 
arrangements united. 

In the organs formed of several superimposed layers, as the alimen- 
tary canal, the bladder, &c, a proper layer of mucous tissue always 
exists between the different coats, which may be regarded as forming 
the transition of this to the internal mucous tissue ; since, if it is inter- 
nal in regard to the whole organ, it is also external in relation to each 
of its different layers. 

Partly on account of these atmospheres of mucous tissue, the adja- 
cent organs and the superimposed layers of an organ, escape for a 
time the diseases which attack one or more of them. Nevertheless, 
the mucous tissue does not insulate them perfectly, so that, in general, 
the disease of an organ or layer finally passes through it, and attacks 
the organ or layer adjacent ; and again it only serves to concur in the 
insulation of the diseases of the organs which depends principally on 
the peculiar structure of each part, and on the differences of the life it 
enjoys. This proposition seems at least very probable, when we re- 
member that, although the nerves and vessels are not lined with this 
tissue, they often escape disease, although all around may have been 
destroyed by suppuration: the character of the disease itself has also 
some influence, for some maladies extend to the surrounding parts 
more readily than others. 

Further, these atmospheres of mucous tissue relate also to the mo- 
tions of the organs, and hence are found abundantly around parts which 
are very movable. 

§ 52. Usually it encompasses the respective parts in their whole ex- 
tent, except the skin, where it is found only on its internal face. Hence 
the skin has been compared, in this respect, to the serous and mucous 
membranes, and even to the vessels ; but the comparison is incorrect, 
since all the hollow organs are enveloped in all parts with the mucous 
tissue. In fact their internal surfaces are not lined with it, so that, 
when opened and drawn out to reduce them into flat membranes, they 
are analogous to the skin. And will not all the other organs present 
the same phenomenon if they are also treated in this manner ? Finally, 
the skin is no exception to this rule, as the epidermis, which covers it, 
may be considered as an indurated mucous tissue, and as an external 
envelope or capsule. 

§ 53. The proper substance, the vessels, and the nerves, of the organs, 
are situated within the special mucous tissue, which may itself be 
divided into two other parts. Each branch of a vessel, of an excre- 
tory duct, or of a nerve in the interior of an organ, has its layer, its 
proper cellular sheath, which is more solid than the rest. Between these 
sheaths we find a looser mucous tissue. The fasciculi and the fibres 
of a muscle are surrounded with proper sheaths, which are arranged, 
in regard to the looser mucous tissue in their spaces, in the same 
manner as is the capsular mucous tissue of a whole organ in regard 



OF THE MUCOUS SYSTEM, OR CELLULAR TISSUE. 87 

to the general mucous tissue. The final element, which possesses a 
definite form, is also enveloped with mucous tissue. 

Thus, in final analysis, the mucous tissue represents a cavity con- 
stantly folding from without inward, which closely envelopes the 
whole body, and all the organs, and even their minutest portions. 

We cannot perceive with the naked eye in all the organs, that the 
quantity of the mucous tissue is in an equal ratio with the other 
compound elements included by them ; many seem even entirely des- 
titute of it. Thus we find little in the brain, spinal marrow, bones, 
tendons, &c, while there is much more in the muscles and the lobate 
glands. 

§ 54. Although some vessels and nerves of large and small caliber, 
wind into the mucous tissue, we cannot consider them as its compo- 
nent parts, since they pass through it only to go to the organs and form 
with it their bases. But the most delicate ramifications of the exhalent 
and absorbent vessels,(l) undoubtedly enter into its organization, and 
very probably have no proper parietes distinct from the rest of this 
tissue. 

As regards chemical composition, the mucous tissue belongs to the 
class of organs formed principally of gelatine. 

§ 55. The mucous tissue is highly elastic, so that it may be ex- 
tended to a great degree, and contracts in the same proportion ; its 
elasticity, however, is diminished by the effects of inflammation and 
other morbid changes, and it becomes fragile. 

The plastic or formative power, is developed in it to a great degree ; 
hence its facility of prompt and complete reproduction, when it has once 
been destroyed ; and hence too it replaces those parts which cannot be 
reproduced in perfection, as the muscles and the tendons. All reproduc- 
tion then commences by the formation of mucous tissue. This tissue 
is destroyed with difficulty. The other vital phenomena, irritability 
and sensibility, are not observed in it ; at least it possesses the former 
only in certain regions, and in a feeble degree ; and even the pheno- 
mena which lead to this conclusion do not positively prove it, since they 
may occur in the muscular system or in the cutaneous tissue, as well 
as in the mucous system. 

§ 56. The mucous tissue includes two different fluids, a serum, ana- 
logous to that of the blood, and fat. 

The serum, unlike the fat, exists in all parts, but not always in the 
same quantity, which seems to be inversely as that of the fat ; thus it 
abounds in the scrotum and eyelids, which normally contain no fat, and 
it collects there more readily than in other places ; an accumulation of 
it constitutes anasarca. The serum of the mucous tissue, like all the 

(1) Absorbent and exhalent vessels do not exist. They have never been seen, but 
have been imagined, to account for the phenomena of exhalation and absorption. 
Before they were thought of, these phenomena were well explained by transudation 
and imbibition. Physiologists owe this doctrine to Magendie and Fodera. Fodera 
thinks that exhalation and absorption depend on capillarity of the tissues, that this 
double phenomenon can exist in all parts, and that the liquids which they contain may 
be carried either by the lymphatics or by the arteries and ^eins. See his Retherches 
experimentales sur Pabsvrption et I'cxhalation, Paris, 1824. F. T. 



88 GENERAL ANATOMY. 

serous fluids, contains an abundance of albumen combined with a small 
quantity of coagulable mucilage and salts. If we may judge trom 
experiments made upon the serum which is collected abundantly by 
blisters between the cutis and epidermis, the ratio of the animal matter 
to water, is less than in the serum of the blood. ( 1 ) 

§ 57. The fat(2) is yellowish and less fluid than the serum ot 
the mucous tissue. This substance occurs in masses of various forms, 
composed themselves of regular, rounded globules or vesicles arranged 
more or less compactly, one against another. The masses and ve- 
sicles are formed of mucous tissue, which contains the fat, but is not 
connected with it, and which unites them altogether. Their size varies, 
although Wolff pretends it is always the same in man, for the small 
masses which they inclose, differ much in volume. The largest are 
generally situated internally, and continue diminishing as they approach 
the circumference, where they are also more compact. Nevertheless 
small masses are found among the large. These have the same vo- 
lume in all the regions of the body, although that of the masses varies 
infinitely. 

In regard to chemical composition, fat differs from all other animal 
substances, as it contains but very little azote : by distillation it is re- 
solved, for the most part, into water and carbonic acid, and a small 
quantity of ammonia. A peculiar acid, which Krell believed he had 
discovered in fat, seems not to exist ; as is the case too with the salts 
and acetic acid mentioned by Thenard,(3) while the peculiar acid he 
thought he discovered in fat, is benzoic acid, (4) according to Berze- 
lius.(5) 

The quantity and nature of the fat is not the same every where. 

This substance presents itself in two states loose, and in combina- 
tion. 

There are parts of the body which contain no loose fat, as the inte- 
rior of the skull, of the brain, of the eye, of the nose, of the organ of 
hearing, the lungs, the intestinal canal, and the glands. 

Much is found, however, under the skin, except in the penis, eyelids, 
and scrotum. It abounds in the face, the neck, the abdomen, the groins, 

(1) Marcet, A chemical account of various dropsical fluids, in the Medico- Chirurg. 
Tr ansae., vol. ii. p. 34-384. Bostock, On the analysis of animal fluids, in same 

journal, vol. iv. p. 53. 

(2) Malpighi, De omento, pinguedine et adiposis ductibus ; in his Epist. anat , 
London, 1686, p. 33. — Jansen, Pinguedinis animalis consideratio phys. et pathol., 
Leyden, 1784.— Wolff, De adipe, in Nov. Act. Petrop., vol. vii. 1789, p. 278.— Reussing, 
Diss, de pinguedine sandet morbosd, Jena, 1791. — Allmcr, Diss, sistens disq. anat. 
pinguedinis animalis, Jena, 1823. 

(3) JJeber die Fettsaure, in Scherer's Allgem. Journ. de Chemie, vol. viii. p. 127. 

(4) Veber die Fettsaure, in Gehlen's Journ. fur Chemie und Physik, vol. ii. p. 275. 

(5) Chevreul has recognized in it, as in many other fatty bodies, two portions, a 
fluid called elain, and a solid called stearin ; this latter very much resembles the 
fat of tallow, but is distinguished from it, as by saponification, we have margaritic 
but not stearic acid. It is white and has but little lustre ; when fused it crystalizes 
on cooling in small needles, the mass of which is terminated by a plane surface. A3 
to elain, it is colorless, and resembles an oil; it is liquid even at four degrees below 
zero, and begins to form an acicular mass at several degrees below this temperature. 
It is inodorous, or nearly so ; its taste is sweetish, and when fresh is not disagre- 
able. F. T. 



OP THE MUCOUS SYSTEM, OR CELLULAR TISSUE. 89 



the upper parts of the extremities, the palms of the hands, the soles of 
the feet, between the voluntary muscles and among their fasciculi and 
even their fibres, around certain membranes, as the peritoneum and its 
prolongations especially the omentum and mesentery, in the pelvis, 
beneath the internal layer of the pericardium, consequently on the sur- 
face of the heart, around the origins of the large vascular trunks, in the 
mediastina, around certain glands, as the salivary glands and kidneys, 
around the nerves penetrating between their fasciculi in considerable 
quantity, and finally within the bones, especially the long bones, 
where it is called marrow. (1) 

It accumulates in those parts especially which execute extensive 
and frequent motions, and in those where it is necessary that the heat 
should be concentrated. It is deficient, on the contrary, in fat persons, 
where it would incommode the functions, and where its existence 
might affect even life. 

The fat, combined with the other immediate materials of organized 
bodies, exists in several places where it is rarely found in a loose state, 
and where even it is never uncombined, as particularly in the brain, (2) 
which, like the nervous system in general, contains a considerable 
quantity of the two different fatty substances. 

The fat does not exist in the substance of the fibrous organs, in the 
cartilages, bones, or serous membranes, either in a loose state or in 
combination ; although it sometimes collects in considerable quantities 
around those parts. 

The fat has not the same consistence every where : thus, it is very 
hard around the kidneys, but softer on the heart and in the orbits of 
the eyes. 

G. Hunter was led to conclude, from the constant deficiency of the 
fat in some parts of the body while it abounds in others, from a greater 
accumulation of serum or air in parts destitute of fat in persons affected 
with edema or emphysema, while, whatever degree of obesity occurs, 
fat never accumulates in these parts even when they are so situated 
that a fluid contained in the mucous tissue would collect in them from 
the fact of its gravity alone, as the scrotum ; from the difference ob- 
served too, even in the most extensive anasarca, between those parts 
of the mucous tissue filled with water and those which before con- 
tained fat ; and from another circumstance, that the fatty portions of 
the mucous tissue do not yield at all to pressure, as do those which 
contain an excess of serum, and that the fat usually cannot pass from 
one place to another : all these facts, we say, led G. Hunter to con- 
jecture that the fat is secreted by a peculiar glandular apparatus, dis- 
tinct from the common mucous tissue, and composed of vesicles. (3) 

(1) Analysis of the marrow by Berzelius, in Gehlen's Journal fur Chemie und 
Physik, vol. ii. p. 287. 

(2) Vauquelin, Analyse de la matiere cerebrale de I'homme ct de quelques ani- 
maux, in the Ann. du Museum naturel, vol. xviii. p. 212-239. 

(3) Wolff was the first to state that the molecules of fat are contained in the spaces 
of the mucous tissue in which they are placed, and not in special cells. Heusinger 

Vol. I. 12 



90 GENERAL ANATOMY. 

Most probably, however, this special apparatus does not exist, and the 
adipose cellules are all produced simply by fatty globules, which pene- 
trate the mucous tissue as the fat forms. Our opinion is founded too 
on the circumstance of the fat appearing in the form of globules inde- 
pendently of the mucous tissue, of which we may be easily convinced 
by destroying a lump .of it. 

RiegePs opinion is still less probable : this physiologist thinks that fat 
is formed in all the glands, but principally in the renal capsules.(l) 

Fat has several uses. Its unctuous nature facilitates the motions of 
the organs ; it is a bad conductor of caloric, and hence it protects 
them from cold by opposing the dispersion of the animal heat. Finally, 
it serves particularly as a reserve of nutriment, although, as it contains 
no azote, it is but feebly animalized. Farther, as its formation is 
favored by rest, so those organs which remain for a long time unused, 
even the muscles'among the rest, are transformed into fat ; on the con- 
trary, fasting, intellectual and bodily labor, and debility from any rea- 
son, cause it to disappear. The facility of its production doubtless 
depends on its slight degreee of animalization : hence the reason why 
it appears, not only in the circumstances above mentioned, but also to 
replace those parts which are wasted, and which have been removed : 
as, for example, the testicle in the scrotum or the eye in the orbit when 
they have been extirpated. 

§ 58. The mucous tissue and the fluids it contains differ very much 
in several respects at different periods of life. Like all other parts, 
they are more fluid in proportion" as the organism is younger. The 
mucous tissue appears at first absolutely homogeneous, very soft, and 
differs but slightly or not at all from serosity, from which it is after- 
wards distinguished by its greater solidity. Hence the reason that 
during the early periods of life we can easily separate parts which 
afterwards become inseparable ; this is seen particularly in those parts 
which are formed of several superimposed layers united by mucous 
tissue. 

The mucous tissue is more abundant the younger the organism is. 
The organism originally, when homogeneous, is formed of this tissue 
alone ; even after the organs are developed, its proportion is still much 
greater, as it contains few substances which are peculiar to it. 
This is proved by the muscles, whose fasciculi are small in proportion 
to the mucous tissue, and by the glands, which are composed of several 
lobes, united by a loose mucous tissue, and easily separable from each 
other. 

The fat is more liquid, thinner, more transparent, and whiter, the 
nearer the organism is to the time of its origin. Nor is its quantity 
the same at all periods of life. In the early periods of fetal existence 

adopted this opinion ; but Beclard has rejected it, and, faithful to the old doctrines) 
admits a special adipose tissue, even as he adopts the opinions of Bichat's school in 
regard to the structure of the mucous tissue. F. T. 

(1) De usu glandularum suprarenaliutn in animalibus, necnon de origine adipis 
dusquisitioanatomico-physiologica, Copenhagen, 1790. Riegel has explained the uses 
ofthefat very clearly, although his little work contains many arbitrary assertions 
wholly unproved, partly true or entirely false. J 



OF THE MUCOUS SYSTEM, OR CELLULAR TISSUE. 91 

it is deficient in those organs which afterwards contain the most. It 
begins to appear at the fifth month under the skin in small isolated 
masses. It exists in masses in this place only, even in the fully grown 
fetus ; for the internal parts, even those where it afterwards abounds, 
as the epiploon, the heart, the surface of the kidneys, the muscles, &c, 
have none or but very little, while it is formed in abundance near the 
surface of the body. This arrangement resembles that in the ceta- 
ceous animals, where little is found internally, but enormous masses 
exist near the external surface of the body. It gradually increases 
also internally ; but, generally speaking, this occurs only towards the 
middle of life. At puberty the fat diminishes externally, as it does in 
the hibernating animals, in proportion as the semen is secreted with 
more activity,(l) and in the same manner also, as in insects, the 
genital organs develop themselves at its expense, so that the neuters 
and those which lose their sex are fatter than the others. 

Finally, the fat not unusually disappears in .all parts of the body at 
an advanced age, and the subject actually wastes. The extremities of 
life then are alike in this respect. Nevertheless, the body of the old 
man differs from that of the infant, in that, although the layers of fat 
diminish in him, the organs are still provided with it, and consequently 
the body always possesses it in a large quantity. A severe and long 
continued dropsical affection can alone remove it entirely, which depends 
doubtless on the fact that the abundant formation of the serum prevents 
that of the fat. 

§ 59. The mucous tissue forms the basis not only of the regular but 
also of the irregular tissues. The history then of all the alterations of 
texture might be given in this place, since they develop themselves 
near it and in it ; but as these alterations present peculiar characters, as 
they appear in the mucous tissue of some organs rather than in that 
of others, we had better mention them when speaking of those organs 
of which they are repetitions, or in which they are developed. 

The induration of the mucous tissue is rather a common morbid 
alteration, and occurs most frequently in very young children. It 
attacks particularly that found under the skin. The fat and serum 
seem to participate in it also, for if we cut into the indurated mucous 
tissue, a yellowish fluid escapes. 

The serum of the mucous tissue accumulates morbidly in general 
anasarca. In this disease the fat disappears more or less completely, 
and is converted into a mucous substance analogous to gelatin. 

The fat itself often varies from the normal state, principally as 
respects its quantity. We have already pointed out in a summary 

(1) H. Reeve, De animalibus hyeme sopitis, London, 1803. — Idem, An essay on the 
torpidity of animals, London, 1809. — Mangili, Saggio di osservazioni per servire 
alia storia de' i mammiferi soggetti al periodico letargo, Milan, 1807- — Idem, Me- 
moire sur la lethargic periodique de quelques mammiferes, in the Annates du 
Museum, vol. x. p. 234. — J. A. Saissy, Rccherches experimentales, anatomiques, chi- 

miques, etc., sur la physique des animaux mammiferes hibernans, Paris, 1808. 

Prunelle, Recherches sur les phenomenes et les causes du sommeil hivernal de quel- 
ques mammiferes, in the Annates du Museum, vol, xviii. p. 20. 



92 GENERAL ANATOMY. 

manner the circumstances of its excess or deficiency. Its general or 
local accumulation is sometimes enormous. Generally speaking, it 
increases in those parts where it is found in a state of health rather 
than in any other, although in other places the ordinary proportion 
exists : we have observed this particularly in the great epiploon. The 
same may be said of the surface of the heart and mediastinum. Thus, 
it is in the epiploon that lipomata are most frequently formed. But we 
must not confound these congestions of fat with the lardaceous 
tumors, which do not deserve this name, as they are simple condensa- 
tions of the cellular tissue, or repetitions of other regular tissues, or 
finally peculiar morbid tissues. 

The lipomata almost always perfectly resemble the normal fat ; we 
rarely find them surrounded with a proper cyst ; they are connected 
intimately with the adjacent fat, although from their size and pro- 
minence they are immediately discovered. Those below the skin may 
be confounded with other diseases, especially with hernias, when they 
are developed in those parts where the viscera appear after leaving their 
cavities ; of this we have seen several instances, and have some pre- 
parations in our cabinet. 

Fat, however, develops itself sometimes irregularly where it does not 
exist in a natural state : as first in the ovaries, then on the internal face 
of the mucous membrane of the intestinal canal, and rarely within the 
skull. In the ovaries we often find hair developed with the fat ; and 
as in the normal state the mucous tissue contains both fat and serum, 
so collections of the latter fluid are almost always found in those ova- 
ries which are overloaded with fat. 



SECTION II. 

OF THE VASCULAR SYSTEM. (1) 

§ 60. The vascular system (syslema vasorum) is composed of numer- 
ous flexible ramifying canals, formed of several membranes, in which the 
fluid of nutrition is perfected, and carried to all the organs and to all 
the parts of the body, and reconveyed from all the organs. As the 
blood constantly returns to the place from which it started, that is as 
it circulates, this system is also called the circulatory. The first name 
is derived from its form, and the second from its function. It comprises 

(1) There are but few general works which embrace the whole of the vascular 
system, because it is formed of so many different portions, and so many views have 
been taken of it, both generally ancl particularly ; both in its outer and inner 
form, we study its properties, functions, and its changes whether regular or irregular 
We may however mention the following as the principal works on the normal* 
structure and functions of the whole vascular system : ScemmerrW Lehre vom 
Banc des mcnschlichen Kcerpers, vol. iv — Bichat, General Anatomy trans bv Hav 
ward vol. i.-Beclard, General Anatomy, trans, by Togno, p. 237. For the proper- 
ties of this system see Haller, Memoire sut la nature sensible et irritable des parlies 
Lausanne, 1756, sect, xi., and in Op. min., vol. i. nos. 13, 14, 15.— Verschuir Dc 



OF THE VASCULAR SYSTEM. 93 

three principal parts, of which two, the arteries (arteries) and the veins 
(vence), contain perfectly formed blood, which is carried by the former 
to the organs, while the latter takes it back from them. . These two 
systems of vessels meet in a common centre, ^he heart, a hollow organ 
with thick muscular parietes, from which the arteries originate, and 
where all the veins empty themselves. The third principal part is 
the lymphatic or absorbent system, (systema lymphaticum, vasa ab- 
sorbentia;) its vessels do .not carry blood, but are filled with the pro- 
duct of digestion, the chyle, or with the residue of the processes of 
nutrition, the lymph. In several respects this system is only an ap- 
pendage of the venous system. 

§ 61. The arteries, the veins, and the heart itself, are also divided 
into two separate systems. The veins of the one, called for this 
reason the veins of the body, carry back all the blood from the organs ; 
and, as the lymphatics terminate in this system, to which they are only 
appended, they carry the chyle and the lymph to the right or anterior 
portion of the heart. The different veins of this system unite in three 
trunks, the upper and lower venre cavse and the large coronary vein of 
the heart ; these open separately into the right auricle. From this 
cavity the blood passes into the right ventricle, thence into the pul- 
monary artery, which carries it into the lungs, where it is subjected to 
the influence of the atmospheric air. 

The ramifications of this artery carry it to the pulmonary veins, 
whence it passes to the left auricle of the heart, then into the left 
ventricle, and it is afterwards conveyed to all the organs. Harvey, in 
1619,(1) first demonstrated the complete circulation of the blood, which 
had already been discovered in some parts by Servet, Colombo, Levas- 
seur, and Cesalpin. As this fluid has peculiar qualities in the veins 
of the body, in the right portion of the heart, and in the pulmonary 
artery ; as it also possesses properties equally peculiar in the pul- 
monary veins, the left portion of the heart, and the arteries of the body 

arteriarum et venarum vi irritabili ct inde oriunda sanguinis directione abnormi, 
Groningen, 1776. On the motion of the blood consult Harvey, Exercitatio de motu 
cordis et sanguinis in animalibus, Oxford, 1628. — Haller, Experimenta de motu 
cordis a stimulo nato ; De motu sanguinis sermo, quo experimenta continentur ; 
De motu sanguinis sermo, quo corollaria experiinentorum tradantur, in Op. min. vol. 
i. p. 60-241. — Spallanzani, De' ifenomeni delta circolazione osservata net giro univer- 
sale de' vasi, Modena, 1777. For the morbid alterations of different parts of the vas- 
cular system, although they are treated of very imperfectly, see Baillie's Morbid 
Anatomy, § 1, 2, 3. — Voigtel, Handbuch der pathologischen Anatomie, vol. i. — Baillie, 
Of uncommon appearances of disease in blood-vessels, in the Trans, of a soc. for the 
improvement of med. and surg. knowledge, London, 1793, vol. i. no. 9.— Sandifort, 
De rarissimo cordis vitio, in Obs. anat. pat hoi., book i. no. 1. ; De cordis et valvularum 
aorta nonnullis vitiis. ibid., no. 2. ; De notabil. vasor. aberrationibu<, ibid., lib. iv. no. 
8. — Corvisart, Essai sur les maladies organiques du cceur et desgros vaisseaux, Paris. 
1806. Burns, Observations on some of the most frequent diseases of the heart, Edin- 
burgh, 1800. These last works, however, treat only of the sanguineous system. 
The Anatomie Medicate of Portal, vol. iii., art. Angiologie, gives a complete history of 
the whole vascular system, both in a healthy and diseased state. 

(1) Harvey, Exercitatio de motu cordis et sanguinis in animalibus, Francfort, 1628. 
— G. Kerr has recently denied the reality of the circulation, (Observations on the 
Harveian doctrine of the circulationoj the blood, London, 1819,) but all his objections 
are easily refuted. 



94 GENERAL ANATOMY. 

while its qualities in all parts of these two opposite systems are the 
same ; finally, as the structure is similar, and differs only in an analo- 
gous manner in the corresponding portions of each in relation to the 
functions they fulfil, we may with Bichat consider both of them as 
separate systems, of which the first is that of black blood, and the 
second of red blood ; even as two circulations were long since admitted, 
viz., the great circulation, performed by the latter system, and the 
small, of which the first is the agent. Each of these two systems is 
composed of a central part, the corresponding half of the heart, of 
a second portion, through which the blood passes to arrive at the first, 
and of a third, through which it passes after leaving the heart. These 
two halves of the heart belong, in situation, connections, and structure, 
the auricle to the carrying system, and the ventricle to the bringing 
system. 

The three principal parts of the vascular system, the arteries, veins, 
and lymphatics, present peculiarities of structure which distinguish 
them from each other ; but they have also certain common characters, 
which identify them as belonging to one and the same system. 



ARTICLE FIRST. 

OF THE VASCULAR SYSTEM IN THE NORMAL STATE. 
A. THE VASCULAR SYSTEM IN GENERAL. 

§ 62. I. The external form of the vascular system is that of a tree. 

On leaving the heart, it gradually divides into trunks, branches, twigs, 
and ramuscules," which continually diminish in caliber. If we suppose 
all these divisions united in a single canal, the form is not a cylinder 
but a cone, whose apex is at the heart, while the base rests on the sur- 
face of the body, where it is formed by the union of the orifices of the 
smaller vessels. We know not the exact relation between the base 
and summit of the cone ; nevertheless, we imagine, from the numerous 
subdivisions, that the difference is very considerable.(l) Thus, al- 
though the vessels diminish in caliber as they recede from the heart, 
this diminution occurs in the branches, and not in the whole system ; 
and even, in each particular case, the orifices of the branches, if united, 
are always broader than that of the trunk from which they come. But 
the branches do not diminish much in caliber in their passage, and 
preserve the same breadth as long as they do not furnish twigs : we 
may be convinced of this by observing vessels which proceed a consi- 
derable distance without ramifying, as the spermatic arteries. Thus, 
although the whole system represents a cone, its parts considered sepa- 
rately are cylinders. 



ol. i. p. 



\ See several different calculations on this subject in Haller, Defdbr. etu»u, 



OF THE VASCULAR SYSTEM IN GENERAL. 95 

§ 63. The .number of divisions in all parts of the vascular system is 
not the same ; a vessel, however, rarely offers more than twenty. 

§ 64. Neither are the angles formed by these divisions always the 
same, although the calibers of the vessels have no marked influence 
upon these angles. Ordinarily they are more or less acute, and in this 
respect vary very much. The spermatic vessels are perhaps those 
which are given off at the most acute angle. Almost all the vessels 
of the extremities also arise at acute angles. 

On the contrary, the trunks coming from the arch of the aorta, the 
coeliac artery, the superior mesenteric, the renal, most of the intercostal, 
and the diaphragmatic arteries arise by almost right angles. 

The superior intercostal and the recurrent arteries of the extremities 
describe an obtuse angle with their trunks. The more modern asser- 
tion, therefore, is entirely false, viz. " that the branches of the vessels 
every where rise at acute angles ;" and some anatomists still admit, 
quite erroneously, the differences of the angles above mentioned 
only according to measurements made on dry arteries.(l) 

§ 65. II. Notwithstanding these divisions, there is an uninterrupted 
communication between the different parts of the vascular system, not 
only by the union of all in common trunks, but also by the connections 
between most of them. This latter arrangement is called anastomosis ; 
it differs considerably in its form and its greater or less frequency in 
the different parts of the same section of the vascular system. 

1. The most usual case is when two vessels anastomose to form an 
arch, while the place of union is not exactly known, and from this 
arch vessels of a smaller caliber arise, as happens around the articula- 
tions and near the intestinal canal. 

2. The communication of two vessels by a small transverse branch 
of little extent is more rare. This arrangement exists, for instance, 
between the two umbilical arteries, where they enter the placenta ; 
they are observed frequently between the umbilical arteries of twins. 
We find an instance too in the anastomosis of the anterior with the 
posterior cerebral arteries, giving origin to the vascular circle of Rid- 
ley. The umbilical vein unites with the vena cava in the same man- 
ner, by the venous canal. This kind of anastomosis is very common 
in the veins of the limbs, especially in those of the superficial layer. 

3. It is still more rare to see two vessels unite at an acute angle to 
form one, the direction of which is between that of the two trunks 
which have produced it. This is the mode of union between the pul- 
monary artery and the aorta in the fetus by means of the arterial 
canal, and between the two vertebral arteries, to give rise before to the 
basilar, and behind to the anterior spinal artery. 

In the last species of anastomosis the two vessels which unite are 
almost equal in volume, while in the other two they often differ very 
much in this respect. 

(1) Walthers, Physiologic vol. ii. § 399. p. 49, 



96 GENERAL ANATOMY. 

With regard to the frequency of anastomoses, we may say, in gene- 
ral, that they are very frequent between the small vessels particularly, 
and that they increase the farther the vessels are from the heart ; so 
that the smallest form a very complex network. Anastomoses be- 
tween the large vessels are rare ; they are most common in the intes- 
tinal canal and the extremities. The largest, that between the pul- 
monary artery and aorta, is only temporary. They facilitate the 
course of the blood, and diminish the inconvenience of obstacles to the 
circulation, and even those which might arise from the destruction of 
the principal large trunks ; as then the anastomosing canals, already 
very large or at least very dilatable in the normal state, permit the 
blood to arrive at the parts. Hence the reason that even the large 
trunks, as the aorta,(l) vena cava,(2) internal jugular vein,(3) and the 
thoracic canal, (4) have been found partially contracted or obliterated, 
and the subject has not suffered from this anomaly. 

§ 66. III. The direction of the vessels is usualhj straight. This 
axiom is true particularly in regard to the trunks and branches ; as for 
the smaller divisions, they are somewhat tortuous : but, in general, the 
the course of the vessels presents differences in this respect independent 
of their caliber, which arise from the nature of the organs. In fact the 
vessels of those organs which change very much in volume are very 
tortuous. This arrangement is well marked in the uterine vessels 
during pregnancy, where the curves are so numerous and so consi- 
derable, that acute angles often result. We observe it also, although 
in a smaller degree, in the vessels of the stomach, of the intestinal 
canal, of the face, of the lips, and particularly in those of the iris, the 
tongue, and the bronchia. This arrangement allows the blood to cir- 
culate uniformly when the organs are collapsed as well as when they 
are dilated ; for in the latter case these vessels lengthen and extend. 
In those organs which are not subject to these changes in volume, but 
which are liable to changes in situation, similar, for instance, to what 
the limbs experience in flexion and extension, this tortuousness of the 
vessels is replaced by their elasticity. 

There are also other instances, where the course of the vessels is not 
straight, but very much curved : this is the case with the arteries of 
the spleen and those of the brain. The purpose of this anomaly 
appears to be slightly to retard the course of the blood. 

(1) Paris, in Desanlt's Journal de chirurgie, vol. ii.— Scarpa, Sur VAncvrisme 
trans, by Delpr, P is, 1309.— A. Cooper and B. Travers, Surgical works— Gra- 
ham in Mcdico-clarurg. trans, vol. v.— Th. Goodisson, in Dublin Hospital reports, 
Dublin, 1818, p. 194. r r ' 

(2) Haller, De gravior. quibusdam aorta venceque cavce morbis Goettin«-en 1794 
§ vm.-Bailhe, in Trans, of a society/or the imp. ofmed. and surg. knowledge, vol! 
i. no. 8. p. 127 -Wilson, ibid., vol. vm. no. 6. An instance of the obliteration of the 
vena cava inferior by inflammation, p. 65.— Hodgson, Diseases of the arteries and 
veins. 

(3) G. Lardner, Case of the obliteration of the internal jugular vein in Edinb 
med. and surg. journal, vol. viii. no. 28. p. 407. ' 

(4) Sir A. Cooper, in Med. records and researches, London 1813 — Flindrin 
Journal de medecinc, vol. lxxxvii. 1791. ' ljU " uon > imi - 'landrin, 



OP THE VASCULAR SYSTEM IN GENERAL. 97 

There are other vessels in which these curves exist only at certain 
periods of life, and are observed when the organs are developed in a 
part which they afterwards leave. Thus, the vessels of the testicles 
are very crooked while these glands continue in the abdominal cavity, 
but they afterwards become straight. 

§ 67. IV. The vascular system, considered in a general manner, is 
symmetrical, that is, the right and left sides, the superior and inferior 
portions, and to a certain extent the anterior and posterior parts of the 
body correspond in this respect. Nevertheless, even the symmetry of 
those parts which are most similar, the right and left sides, is much 
less than that observed for instance in the nervous system. Thus, the 
heart is not perpendicular, nor situated so that its axis corresponds to 
the median line, neither are the unmated trunks of the arteries, veins, or 
lymphatics, placed upon this line. Finally, the corresponding vessels 
of the two sides are not arranged in the same manner : thus, for in- 
stance, the arteries of the head and superior extremities arise from a 
common trunk on the right side, while on the left they come off 
from the aorta by separate trunks. In fact the symmetry seems a little 
greater when we consider the vascular system as a whole ; for then 
we find, for instance, the trunk of the veins of the body on the right 
side, that of the aorta on the left, and that of the absorbents in the 
centre ; but the symmetry is, at the best, very imperfect. In animals, 
particularly those far removed from man, and in the fetus, the 
arrangement is more symmetrical. 

§ 68. V. The distribution of the vascular system presents numerous 
and very considerable differences, since the origin and distribution even of 
the largest vessels varies. This system is undoubtedly that in which 
we find the most anomalies. When an anomaly exists on one side, 
a similar or analogous one is usually observed on the other. These 
anomalies frequently add to the symmetry, but often also they render 
it less evident. 

Neither is it rare that anomalies of the same kind are observed jn 
the upper and lower parts of the vascular system. Thus, we have 
met with two instances where in the same subject the left renal artery 
divided, and the vertebral artery arose immediately from the aorta. 

On the contrary, the anomaly of one portion of the vascular system 
has usually no influence on the course of the others. Hence the rea- 
son why anomalies of the arteries are so common in all the parts of 
the body while the veins do not vary, and vice versd. The anomaly of 
one part often approximates it to the normal formation of another ; an 
effect which is produced, for instance, by the development of large ana- 
stomoses or of the large superficial vessels in the arterial system. 

§ 69. With regard to its internal form or its texture, the vascular 
system in almost every part is composed of several layers. 

The internal layer is the most essential, as it exists in every part of 
the system, and passes uninterruptedly from one to another of its prin- 
cipal divisions. This membrane is very thin, whitish, more or less trans- 
parent, homogeneous, and has no trace of fibres ; but it differs very 

Vol. I. 13 



99 GENERAL ANATOMY. 

much in regard to its thickness, extensibility, and solidity, not only in 
different portions, but also in different parts of each principal portion. 
It is loosely attached to the inner and outer surface of the membrane 
next to it, and may easily be detached, and represent a separate organ. 
The serous membranes are those with which it seems the most ana- 
logous, and perhaps it connects them with the mucous system. 

Does it secrete? We find an unctuous fluid in the vessels of the 
cadaver, even in those parts which contain no blood, as the arteries ; 
but this fluid may perhaps be the serum of the blood or the result of trans- 
udation after death. Bichat,(l) who considers the internal membrane 
only as an epidermis to protect the vessels against the blood, thinks 
this fluid is not produced by the vital action of the arteries, founding 
his opinion on this fact, that the internal surfaces of the arteries when 
deprived of blood adhere intimately. But this phenomenon proves 
nothing against the opinion, since the example of the serous mem- 
branes announces that the fluid to which it refers may be the agent of 
this adhesion, and because we find adhesions in the mucous membranes. 

In several parts of the internal membrane are folds called valves 
(valvules) which project within the vessels. Usually the form of these 
folds is semi elliptical, adhering by their convex edge, while the straight 
edge is unattached. Their arrangement is always such as to oppose 
the reflux of the blood when its course is impeded by any cause ; because 
the retrograde motion of this fluid separates them from the parietes of 
the vessel, and adjusts them to each other. On the contrary, when 
the column of fluid moves uninterruptedly, it forces them against the 
sides of the vessel. We almost always find several of these valves in 
the same part ; this arrangement, while it increases the obstacles to 
the reflux of the blood in the first case, impedes it much less in the second. 

The only membrane outside of the internal membrane which is 
common to the whole vascular system, is that called the cellular or 
nervous tunic (tunica cellulosa seu nervea) ; but in all the arteries and 
in .the large veins, between this and the internal tunic, we find another, 
called the fibrous, muscular, or fleshy tunic, (tunica fibrosa, muscularis, 
seu carnea.) The cellular coat blends insensibly with the mucous tissue 
disseminated through the organs ; it consists only of a thicker and 
denser mucous tissue, the resistance of which is so great that it forms 
a cylinder different from the rest of this tissue. The line of distinction 
between this and the fibrous tissue being as distinctly drawn, we ought 
to consider it as a peculiar membrane belonging to the vascular system. 

Scarpa asserts that we should not regard the cellular tunic as 
belonging to the vessels, as it only covers them externally, to keep 
them in place, and to unite them to the parts adjacent, and that it is 
the soft and extensible mucous tissue of these latter. But we cannot 
agree with him, since the cellular coat of the vessels is more closely 
united to their fibrous membranes than to the adjacent mucous tissue 
from which it appears to be distinct. Vessels are every where found 

(1) General Anatomy, vol. i. p. 313. 



OF THE VASCUEAR SYSTEM IN GENERAL. 99 

surrounded with this funnel-like layer, which is attached to the fibrous 
membrane by a thin layer of loose mucous tissue, and which is evi- 
dently distinct from the mucous tissue found between the organs. If 
we divide an artery, taking care to cut the fibrous membrane only in a 
part of its circumference, we can easily raise the dense and whitish 
cellular tunic in the form of a continuous membrane, and with the 
blade of a scalpel can neatly detach it from the subjacent cellular 
tissue. 

It is principally to this external membrane that the curves in the 
vessels are to be ascribed^, which disappear as soon as it is cut. There 
is no fat in its interstices, nor does it furnish any serum. It does not 
penetrate internally between the other membranes. 

§ 7G. The vascular system contains the common nutritious fluid of all 
the organs; but its own proper substance is supplied by peculiar vessels 
(vasa vasorum) which are distributed in it. This arrangement is not 
confined to that portion of the vascular system which carries an im- 
perfect nutritious fluid ; it extends to all. The vessels which compose 
it arise from those near, and rarely or never from the artery to which 
they belong. They divide and anastomose in the cellular membrane 
before penetrating the internal tunics. Almost all their ramifications 
are appropriated to the fibrous membrane, at least the internal coat 
receives very few ; the arteries and veins reciprocally accompany them 
there. 

The existence of the absorbent vessels is very probable ; but it has 
not been demonstrated :(1) although blood has not been diminished in a 
portion of avessel comprised between two ligatures. (2) This experiment 
proves only that the action of the absorbents does not extend into the 
cavity of the vessels. 

§ 71. The nerves of the vessels are not numerous ;(3) they gene- 
rally form a network on their surface. The nervous system of organic 
life furnishes twigs to most of the vascular system, but not to the whole, 
since those of the vessels of the extremities come from the nervous 
system of animal life. (4) 

§ 72. The most delicate branches of the vessels are called the capillary 
vessels, (vasa capillaria.) This term is applied both to the final ramifica- 
tions of the arteries and to the origins of the veins. Ought we to con- 

(1) It seems to be demonstrated, not only by the microscopical observations of 
Malpighi and Leeuwenhceck, and by the injections of Ent, but also by those inflam- 
mations where there is no blood effused, and where the lymphatics are gorged with 
it. In this case, the excess of this fluid which distended the blood-vessels has been 
absorbed by the absorbents. This explains the utility of means to quicken the 
absorption in inflammation. See Cruikshank, The anatomy qf the absorbent vessels, 
ch. x. p. 20. — E. A. Lauth, Essai sur les vaisseaux lymphatiques, Strasburg-, 1824, 
sect. ii. p. 12. — Alard, De V inflammation des vaisseaux absorbans lymphatiques, der- 
mo'ides, et souscutanes, &c, 2d edit., Paris, 1824. F. T. 

(2) Bichat's General Anatomy, vol. i. p. 321. 

(3) The nerves of the vessels are very numerous, especially in the thoracic and 
abdominal cavities. F. T. 

(4) VVrisberg, De nervis arterias venasque eomitantibus, in Sylloge eomm. Goettin- 
gcn, 1800. 



100 GENERAL ANATOMY. 

sider the capillaries as a separate system, distinct from the rest ^j" the vas- 
cular system, in which the arteries terminate, and from which the veins 
and the exhalent and absorbent vessels arise? Bichat has adopted th 1S 
opinion. Autenrieth goes still further, for he pretends that the capilla- 
ries, even as regards their form, constitute a system intermediate be- 
tween the arteries and veins, saying that the final ramuscules of the 
arteries anastomose with the first twigs of this system, and mat these 
unite in trunks which afterwards ramify a second time ; so that accord- 
ing to him the form of the capillary system is the same as that of the 
vena porta.(l) But this.form which Autenrieth assigns to the lym- 
phatic system does not depend upon positive observations. 1 he most 
minute injections demonstrate only two series of ramifications and not 
four. On the other hand, Bichat has too widely separated the capil- 
lary system from that of the arteries and veins. He has extended the 
limits of this system too far, in saying that it furnishes all the vessels 
designed to nourish the organs. Nutrition ought necessarily to be car- 
ried°on without the cavity of the vascular system, and cannot take 
place unless the nutritious fluid leaves the vessels which contain it. 
It is not true then, even in this respect, that the organized body should 
be considered simply as an assemblage of vessels. 

§ 73. Nevertheless, the capillaries differ in several respects from 
the larger divisions of the vascular system : 

1 . In the nature of the fluid they contain. Blood is not found every 
where as in the large branches of the arteries and veins ; the small 
vessels also carry other colorless fluids, particularly serum. 

2. The heart has less influence on the motion of the fluids they 
contain. This is demonstrated by the absence of pulsation in the 
venous system, which is in a great measure explained in this manner : 
by the arbitrary increase in the activity of these vessels in inflammation, 
which is seated principally in them, or at least takes place much more 
rarely in the large vessels ; and finally, because those secretions which 
are performed in the limits of the capillary system are independent of the 
heart's action, to a certain extent. 

§ 74. The capillaries do not extend equally far in all parts, neither 
is there every where the same proportion between the blood and the 
other fluids they contain. We rarely can demonstrate the presence of 
very minute vessels in the cartilages, in most of the fibrous organs, the 
epidermis, the nails, the hair : those which we sometimes find there 
when in their normal state never contain blood. The bones, the skin, 
the glands, the parietes of the vessels, the serous membranes, and some 
fibrous organs, are furnished with capillaries, some of which contain 
blood, and others colorless fluids. By means of fine injections, and 
sometimes even during life, as after certain irritations from diseases, 
&c, we see parts, which at first view seem entirely destitute of vessels, 
covered suddenly with a vascular network. In other organs, as the 

(1) Physiologic, vol. ii. p. 138. 



OP THE VASCULAR SYSTEM IN GENERAL, 101 

muscles, the capillaries appear to carry red blood only ; nevertheless, 
we must observe that the coloring substance is found also outside of 
the vessels. 

Finally, the relation between the blood and the colorless fluids is 
no where always the same. The examples mentioned of the blood 
penetrating parts usually colorless furnish already one proof. Nor 
ought we to rely upon the injection of colored liquids to discover 
the true limits of the blood in the capillaries, since, when it suc- 
ceeds, and fills even the smallest vessels, it tinges red, parts which, 
like the serous membranes, are colorless, or at most but very slightly 
colored during life. 

§ 75. The vascular system contains the fluid of common nutrition, 
carries it to all the organs, and sends it into all. How does this fluid 
escape from its cavity 1 How does it penetrate into them 1 We must 
observe first, that absorption and exhalation take place very pro- 
bably only in the most delicate twigs of the vascular system, because 
all the vessels are provided with smaller vessels, conductors of the 
blood which is distributed to their parietes, because these vessels 
ramify infinitely, and finally because there are no plausible reasons for 
admitting the contrary opinion. 

But how do these fluids enter into these most delicate ramifications, 
and how do they come from them % Are the terminations of the arte- 
ries and the origins of the absorbents closed or open ? Neither in the 
smallest nor in the largest vessels has observation demonstrated chasms 
in their parietes, or orifices at their extremities. Nevertheless, constant 
openings probably exist, but their diameters vary with the degree of 
vital activity they possess. At least these openings exist necessarily 
where the fluids enter and depart. But absorption and exhalation are 
never interrupted, and it is impossible to demonstrate that the sub- 
stance is destroyed and reproduced alternately, in infinitely small 
spaces, at the extremity of the vascular system. 

§ 76. Tt is still less probable that the different portions of the vas- 
cular system every where form closed cavities which do not communi- 
cate with each other. We have already (§60) said that the absorb- 
ents are only an appendage of the venous system, from which they 
arise by several large trunks : there can be no doubt in any respect in 
regard to this. That the final twigs of the arteries and veins commu- 
nicate is less certain.(l) Nevertheless, the opinion of those who refuse 
to admit this communication, and who think that the blood is effused 
between the two orders of vessels, either into the substance of the 
organ or into special cells, or who believe that the arterial blood is 

(1) Among the moderns who do not admit this communication arc Doellinger and 
Willbrand. The former thinks that the terminations of the arteries have no parietes, 
that the blood moves freely in the solid substance of the body, which he term* mu- 
cous, and partially continues its course, to pass into the venous and lymphatic ves- 
sels arising from this substance, as the arteries terminate in it. According to 
Willbrand, all the blood changes into organs and secretions, and these organs, 
becoming in a measure fluid, are formed again into venous blood and lymph, which 
continue to circulate. * • _T, 



102 GENERAL ANATOMTT. 

changed at the extremity of the arteries into the substance of the 
organs, and that the venous blood itself is formed from all parts at the 
expense of this same substance, this opinion, we say, is at least very 
improbable ; for, 

1. Some substances although coarse, provided they are sufficiently 
warm and consequently fluid, pass easily from the arteries into the 
veins of a part whose temperature is also properly elevated. 

2. Microscopic observations made on the transparent parts of living 
animals, as the bronchia} of the salamander, the mesentery and the 
swimming membranes of frogs, the tails of fishes, &c, demonstrate 
clearly the uninterrupted continuance of the arteries with the veins. 

3. This phenomenon is often observed under the microscope in the 
same transparent parts when they have been well injected. 

But these anastomoses are always very narrow. They suffer only 
one globule or a very small number of globules of blood to pass at 
once, and those admitted by certain anatomists between the arterial 
and venous branches of a large caliber, as for instance between the 
spermatic arteries and veins,(l) have been long rejected by reasonable 
men. (2) In one part of the body only, the lungs, does the system of 
red pass to that of black blood in a manner opposite to that which is 
usual. It is true that large anastomosing branches exist between the 
arteries and pulmonary veins ; but they are rather anastomoses be- 
tween vessels of the same kind, since the small branches of the pul- 
monary artery carry red blood. 

The transition from the arteries to the veins does not every where 
take place in the same manner, either as respects the size of the ves-. 
sels, or the other conditions of the phenomenon. Sometimes the 
artery only folds upon itself, and thus becomes a vein, and again small 
branches are detached, which empty into the vein adjacent. But very 
probably in this case the union takes place by a small intermediate 
branch, of which consequently one half is venous, the other arterial. 

§ 77. The relation of the vessels to the organs may be considered in 
several points of view : 1st, in regard to the quantity of nutritious 
fluid which arrives at the organs and which returns from them, and 
consequently, other things being equal, in regard to the greater or less 
size of the vessels ; 2d, to their number ; 3d, to their direction • 4th to 
their divisions and anastomoses ; 5th, to their place of origin ■ 6th and 
lastly, to their length. 

§ 78. 1st. Abundance of vessels and abundance of nutritious fluid 
are not synonymous, since an organ which has many vessels of a small 
caliber, as a bone, may nevertheless not receive abundance of nutritious 
fluid. The secretory organs are those in which the vessels are pro- 
portionally the largest. Next comes the muscular system, the nervous 
system, the bones, and finally the fibrous organs and the cartilages. 

(1) Lealis Lealis, Dc par tibus semen conf., Leyden, 1707. 

(2) G. Martin, Reflections and observations on the seminal blood-vessels in \Ted 
essays and obs. of Edin., vol. v. no. 19. ' 



OP THE VASCULAR SYSTEM IN GENERAL. 103 

The cuticle, the enamel of the teeth, the amnion, and the tunica arach- 
noidea, receive no vessels, at least in man. 

2d. Every organ is usually supplied with several vessels. The 
unmated organs, formed of two halves more or less intimately united 
on the median line, as the brain, the nasal fossae, the thyroid gland, 
the larynx, the stomach, the liver, the uterus, the bladder, and the 
penis, not only receive two vessels of the same name — the one on the 
right side, and the other on the left — but also each organ, without re- 
gard to volume or its importance, in more than one point receives ves- 
sels which often arise from very remote parts of the sanguineous sys- 
tem, and which usually anastomose near, or within this organ. Thus 
the internal carotid and vertebral arteries proceed on each side to the 
brain, and there anastomose with each other and with those of the op- 
posite side. The spinal marrow, besides the posterior and anterior spi- 
nal arteries, receives a great many vessels from the aorta, which pass 
through the intervertebral foramina. The thyroid gland receives on 
each side two arteries, a superior and an inferior, which anastomose with 
each other, and with their congenitals. So four arteries are given off 
to the stomach, two to the intestines, four to the uterus, and an equal 
number of veins arise from these organs. The kidneys receive two, 
or even a greater number of arteries, more frequently than one ; and 
the number of those belonging to the renal capsules is very considera- 
ble. All the muscles and bones are supplied with vessels which enter 
in several points. In certain organs, possessing but one vessel, as the 
eye, which receives only the opthalmic artery, we find an equivalent 
for this arrangement in the number of anastomoses. But one vessel 
is rarely so much larger than the rest, that we have reason to say with 
Walther,(l) that each important organ receives but a single principal 
vessel. 

3. The vessels generally proceed in almost straight lines. When 
we find exceptions to this rule, the curves of the vessels are attended 
with a change in their caliber, or in their form, as in the hollow organs, 
and then consequently are not constant ; but they sometimes depend 
on other circumstances of which we are ignorant, and are then con- 
stant as in the brain. 

4. JL vessel never enters or leaves an organ, unless it be more or less 
divided. Of this we may be convinced by looking at the brain, the 
eye, the tongue, all the organs of secretion, and the muscles. The 
vessel is generally divided near the organ, but sometimes at a certain 
distance from it. The muscles furnish an instance of the latter. In 
this respect we do not always find the same arrangement, and the 
elongation of the branches makes the vascular trunks more numerous, 
as we can easily perceive in the kidney. These branches almost 
always anastomose together. We have before mentioned the differ- 
ences in regard to the number and size of the anastomoses. 

(1) Physiologic, vol. ii. p. 55. 



104 GENERAL ANATOMY. 

5. The vessels do not always arise from the same point, as we have 
already stated, (§68,) and it matters little, either to the development 
or the function of an organ, from what point its vessels arise, whether 
they proceed difectly from the aorta, or the vena cava, or come from 
secondary trunks. Thus the left vertebral artery often detaches itself 
from the arch of the aorta ; the inferior thyroid artery is anomalous in 
the same manner, or presents other variations. The renal artery arises 
sometimes from the primitive iliac, or even from the internal iliac ar- 
tery ; the three branches of the cceliac artery come directly from the 
aorta in some subjects ; in others their trunk unites to that of the su- 
perior mesenteric artery, &c. All these facts prove that the importance 
and individuality of an organ are not lessened because its vessels 
belong to those of the second order, as Walther says.(l) 

6 th. The origin of the vessels is generally not very remote from 
the place where they enter the organ to which they belong ; and we 
rarely see one passing through any considerable space, unless it sends 
off branches to those parts before which it passes. When the con- 
trary takes place, as in the ovaries, the testicles, the brain, the contra- 
diction is but apparent, and explains itself easily, by the primitive 
situation of those organs : thus the testicles and ovaries are formed 
very near the place from whence the spermatic arteries arise ; and in 
the early periods of life, the neck is so short that the brain rests imme- 
diately on the point from whence its vessels are derived. 

§ 79. We can make but few general observations on the activity of 
the vascular system, because, like the structure, this varies in its dif- 
ferent component parts. We can only say, it is to a certain degree 
elastic, extensible, and contractile, and insensible in the healthy state. 
A dispute still exists, whether it be susceptible of vital contraction, or 
in other words, if it be irritable. The heart and the absorbents cer- 
tainly possess irritability,(2) but observations on the arteries and veins 
as well as the results drawn from them are contradictory. Hal- 
ler has never seen stimulants produce contractions, except in the 
trunks of the venee cavse, although he does not deny the irritability of 
the arteries exactly for that. (3) This subject will be better discussed 
at the end of the remarks on each of the three portions of the vascu- 
lar system ; for, in regard to this, the phenomena are not the same 
in all. 

§ 80. The vascular tissue is composed of several parts entirely dif- 
ferent from each other ; hence, this very complex form is one principal 
cause why it varies so much at different periods of life. The princi- 
pal parts in the history of its development are the inquiries 1st, if 
certain parts of the system appear before the rest, and what these 
parts are ; 2d, the investigation of its mode of origin ; 3d, the study 

(1) Walther, loc. cit. p. 54. 

(2) Verschuir, Diss, de arter. el venar. vi irritabili, Groningen, 1766.— Hastings, 
Diss, de vi contractili vasorum, Edinburgh, 1820. 

(3) Mem. sur la nature sensible et irrit. des parties, Lausanne, 1756. Sect xi. 
De part. carp. hum. prose, fabr. vol. i. p. 140. 236. 



OF THE VASCULAR SYSTEM IN GENERAL. 105 

of the relations which exist at different periods of life between the 
systems of red and black blood, and between the large and small cir- 
culatory systems ; 4th, that of the mutual relations of the vessels, as 
respects number and capacity, at different periods of existence. 

§ 81. 1st. We are deficient in exact observations relatively to what 
parts of the vascular system are formed first, either in man or in the 
mammalia. Nevertheless, we may admit, as almost certain, that the 
veins appear before the arteries, and that the first are those of the umbili- 
cal vesicle ; for it is proved, in birds, that the vitelline veins, and particu- 
larly the omphalomesenteric, are soonest developed ; now the umbilical 
vesicle in man corresponds exactly with the vitelline sac of birds.(l) 

Nevertheless, it is not improbable that, in the body of the human 
fetus, the principal trunk of the arterial system, the aorta, arises at 
least at the same time as the veins, or perhaps before them. Thi3 
conjecture acquires some weight, when we regard : 1st, the arrange- 
ment of the vascular system in the acephalous monsters ; and 2d, the 
manner in which this system is formed in the animal kingdom. In 
supposing it to be true, there is first formed on the anterior face of the 
vertebral column a long canal which ramifies at its two extremities, 
and which blends above, in the place where the heart afterwards 
exists, with the vena porta, with which it probably communicated 
before, only by small twigs. (2) 

2d. As to the mode of development of the vessels, we learn the 
following from observing what occurs in the egg. (3) When at some 
distance from the embryo, we see in the membrane of the yolk, which 
is at first homogeneous, certain rounded, circumscribed rents, which 
are filled with a mass more fluid. These rents are, at first, entirely 
separated from each other, and appear like islands in the rest of the 
mass. New lacunar are gradually formed in the substance of the 
membrane of the yolk, which increase the number of islands, and 
give rise to a fine network of vessels which ramify exceedingly ; 
these soon contain real blood instead of the clear thin fluid which first 
filled them. This vascular network is the commencement of the 

(1) We do not hesitate to use this expression, (notwithstanding the celebrated 
Osiander (Goetteng. Anz. 1814. part 163, p. 1627.) has declared the umbilical vesicle 
to be a morbid abnormal formation, inasmuch as it is never found in the well- 
formed fetus, but only in monsters,) because we have hitherto found it, by careful 
examination, in every fetus where it had not disappeared, and all these fetuses 
were well formed. That the formation of the fetus has no effect on the existence 
of this vesicle, is shown by the observations of the best anatomists, of whom we 
shall mention only Albinus, Hunter, Wrisberg, and Blumenbach, who all observed it 
in the perfectly normal embryo. 

(2) We only mention these as probable conjectures, and, to prevent all false inter- 
pretations, we would have them understood as such. 

(3) Among the modern authors on this subject, we would distinguish Rolando, 
Sur la formation du carnr et des vaisseaux arteritis, veineux ct capillaires ; in the 
Journ. complement, du Diet, des Sciences Medicals, vol. xi. p. 323, and vol. xii. p. 
34. — Pander, Memoiresur le developpement du poulet dansVceuf; same journal, vol. 
xiv. p. 306.— Home, Observations on the changes of the egg during incubation,. 
with notes by Prevost; in the Archives generates de medecine, July, 1823, p. 451. — 
Prout, Experiences sur lea changemens qui arrivent dans les principes fixes dc Vasvf 
pendant V incubation ; same Journal, September, 1823, p. 119. — F. T. 

Vol. I. 14 



106 GENERAL ANATOMT. 

omphalomesenteric vein ; its trunk is not the first portion formed, 
but the ends of the vessel appear soonest ; these gradually unite into 
branches, and finally produce the trunk. At first, the vessels 
have no proper parietes which are distinct from the rest of the sub- 
stance, and represent only lacunae, channels hollowed in this sub- 
stance ; but this insensibly accumulates still more around them, and 
then their parietes appear, the structure of which is slowly and 
gradually developed. , 

3d. When the omphalomesenteric vein is thus once formed, the rest 
of the vascular system produces itself as follows, concluding always, 
as we are obliged to do, from the results furnished by the organo- 
genesis of birds. The vein bends from below upwards, and dilates on 
the anterior face of the body of the fetus to form the heart. From 
this the trunk of the arteries of the body arises, which carries the 
blood to the organs, and after this we see the accompanying veins. 
The omphalomesenteric artery next appears. We do not yet know 
positively, whether the umbilical veins, like the omphalomesenteric 
veins, are formed before the umbilical arteries, or if the reverse be 
true ; but the former is more probable. 

In examining the thing more attentively, this is the progress of for- 
mation. The vessel into which the omphalomesenteric vein opens, or 
to speak more exactly, into which it is changed, is the vena porta. 
This, which at a later epoch, finds itself simply inclosed in the general 
system of the veins of the body, constitutes, at present, the principal 
trunk, and, at its upper part, produces . the heart. The heart appears, 
at first, like a half ring lying loose ; the portion first seen, is the left 
ventricle. Immediately after, the trunk of the aorta shows itself, 
appearing as a considerable dilatation. A little later the upper extre- 
mity of the vein dilates, then contracts before the venous trunk, and 
thus produces the auricle. These three vesicles are, at first, separated 
by folds, very long in proportion, of which one, that between the ven- 
tricle and auricle, is called the auricular canal, (canalis auricularis.) 
These folds soon disappear, and the three vesicles approach each 
other. All the parts which are finally double, are still single at this 
period. 

At the same time the arrangement of the rest of the vascular sys- 
tem is perfected. The vena porta reunites to the umbilical vein, with 
which it ramifies in the liver. It is only then that the blood it con- 
tains commences to circulate there and reaches the heart by passing 
through the hepatic veins. Nevertheless, during the period of fetal 
existence we can trace in the venous duct (ductus venosus) the pri- 
mitive arrangement of the vena porta, and the important part it at first 
performed. The venous duct extends from the umbilical vein and 
vena porta, on the infenor face of the liver, to the inferior vena cava, 
and consequently conducts a part of the blood immediately into this 
last. We sometimes see the primitive arrangement preserved even 
through life, when the whole trunk of the vena porta opens directly 
into the vena cava. 



OP THE VASCULAR SYSTEM IN GENERAL. 107 

While these phenomena take place, the heart continues to develop 
itself. Of all its parts the auricle first becomes double ; an imperfect 
septum descends from its circumference, and floats in its cavity, so that 
the two parts communicate, at first, by a very broad opening. The 
interauricular canal, and the common trunk of the veins of the body, 
the umbilical vein, and the vena porta, opens into the auricle at 
the place of this septum. The doubling of the ventricle does not 
take place in the same manner, but it depends in some measure on 
gemmation, and is produced by the prolongation of the primitive por- 
tion at its upper part. The right ventricle appears, first, as a small 
tubercle, which gradually extends itself towards the summit of the 
heart, and communicates with the left ventricle, not only when it first 
appears, but even after. This communication takes place at the upper 
part of the two ventricles, because, at first, the left cavity only pro- 
longs itself. Hence, why the aorta arises, at first, from both ventri- 
cles. The pulmonary artery is the last to detach itself so as to con- 
stitute a distinct trunk, but it was indicated before along the aorta, In 
fact, at first, this latter, which arises solely from the heart, divides, at 
some distance from this organ, into two branches at least, which soon 
unite to form it's descending portion. As the aorta is blended gradually 
with the ventricle, the bifurcation is depressed also, and when one of 
the two branches separates itself entirely from the other, by complet- 
ing the formation of the opposite portions of their circumference, the 
pulmonary artery appears forming a distinct trunk. But as all the 
cavities of the heart communicate, the pulmonary artery continues 
not only at first, but during the whole of fetal existence, with the 
aorta, of which it constitutes the second root. Nevertheless, as it 
also divides at the same time into two branches, which proceed each 
to a lung, the continuation of its trunk, properly so called, that portion 
between the point where it bifurcates, and that where it is implanted 
in the aorta has been particularly termed the arterial canal, or the 
canal of Botal. (Ductus arteriosus s. Botalli.) 

The vascular system is then formed at its commencement, at least, 
of parts which do not afterwards exist. On the contrary, during the 
latter periods of fetal life the number of these parts is greater, and 
several exist then which disappear after birth. The circulation is at 
first single, and even after the different systems are formed, the line 
of distinction between the systems of red and black blood is not 
drawn with precision. Some of these supernumerary parts which 
latterly are effaced, trace the primitive formation when the parts were 
not so numerous as in the perfect state : all relate to the connec- 
tions of the fetus with external objects. The arrangement of the 
vascular system causes a circulation entirely different from that seen 
in the adult; it varies from the latter, particularly in this, that all the 
organs do not receive blood from the same source ; the small and large 
circulations are not yet completely distinct from each other. In fact, 
the vena cava inferior during the whole period of fetal existence, 
opens more into the left than into the right auricle, so that it pours 



108 GENERAL ANATOMY. 

immediately into the former cavity the blood of the umbilical and 
omphalomesenteric veins, mixed with that of the inferior parts oi the 
body ; from the left auricle the blood, mingled with that winch comes 
from the pulmonary veins, passes into the left ventricle, which then 
sends it through the aorta into the carotid and subclavian arteries; 
One portion goes to the lower part of the body. From these organs 
the blood returns to the right auricle by the jugular and subclavian 
veins ; from the right auricle it passes into the right ventricle, where 
it arrives at first alone, but afterwards, when the orifice of the vena 
cava inferior also opens into the side of the right auricle, it mixes 
with the blood from this last vessel. The right ventricle causes it to 
pass by the pulmonary artery, partly into the lungs, and partly also 
by the arterial canal into the descending aorta, where it mixes with 
that which comes from the trunk of the aorta ; from thence it goes 
into the lower part of the body, which is larger than the upper por- 
tion. The descending aorta divides at its inferior extremity into two 
large trunks, the umbilical arteries, which, arriving at the umbilical 
cord, go to the chorion of the ovum, and at a later period principally 
to the placenta, where they are continuous with the roots of the un> 
bilical vein. 

Thus, the head, neck, and arms continually receive almost all the 
blood which returns from the placenta by the umbilical vein, but they 
receive it mingled with that which returns from the lungs and the 
inferior part of the body. On the contrary, the blood which circulates 
in all the other parts, has already circulated in the preceding, and con- 
tains only a small portion of that which arrives at the right auricle, 
and which, passing from there into the aorta, is not propelled by it to 
the superior parts of the body. Although the blood which returns 
from the placenta does not arrive at the first organs pure, they receive, 
however, a quantity greater than the others. 

When the formation of the vascular system is finished after birth, 
the systems of red and black blood are totally separate ; they com- 
municate only by their extremities, in the lungs on one side, and in the 
other organs in another, and no part of the blood can arrive at these 
organs, unless it has passed through the lungs. But the blood of the 
pulmonary veins does not mingle, except with that which goes to the 
upper part of the body ; and before this fluid has arrived at the lungs, 
the arterial canal removes most of that which the right ventricle 
throws into the pulmonary artery, even as the insertion of the vena 
cava inferior into the left auricle causes the blood which returns from 
the lower parts of the body to flow almost entirely into the aorta, while 
a small portion only goes to the lungs. The pulmonary " artery 
receives but a small portion of the blood which comes to the right 
ventricle. The small circulation then does not form a separate sys- 
tem ; it is only an appendage of the large, since the arteries of the 
lungs arise from a vessel which carries its blood to other parts also ; 
and its veins unite with the inferior vena cava, which receives the 
blood from other organs. The arterial canal has been called, also, the 



OF THE VABCULAR SYSTEM JN GENERAL. 109 

derivative canal, because it turns aside the blood before it arrives at 
the lung. 

These differences depend principally on the inaction of the lungs, 
since after birth the small and large circulations are not separated, ex- 
cept on account of the changes which the blood experiences in the 
organ, and which are caused by the air which rushes there. Pro- 
bably the lung is replaced to a certain extent in its functions by the 
placenta, so that the umbilical arteries and veins may be compared to 
those of the pulmonary system. But the small circulation, which is 
carried on through the placenta, is not separate from the large, since 
the umbilical arteries arise from the descending aorta, the umbilical 
vein and stomoses, directly and indirectly, with the vena cava inferior ; 
and the blood which comes from the placenta mingles, both in the au- 
ricles and at the union of the pulmonary artery with the aorta, with 
that which returns from the organs of the body. Thus, in the fetus, 
the blood which returns from the placenta, and that which comes from 
the organs, is not pure in any part of the circulation. On account 
of this peculiarity, and doubtless because the lungs are very imper- 
fectly replaced by the placenta, there is no marked difference between 
the arterial and venous blood, either in the human fetus, or in those 
of the other mammalia. 

4. With regard to the capacity of the vascular system, and the 
number of vessels at different periods of life, we may say, generally, that 
when the vessels are once formed, their number and diameters are pro- 
portionally greater, in the early, than at subsequent periods. The heart 
of the fetus is unquestionably much larger in proportion to the rest of 
the body, the nearer it is to the period of its formation. . How inconsi- 
derable are the only ramifications of the umbilical vessels ! The same 
remark applies to the small vessels. The latter, and generally speaking 
the whole vascular system, are much more easily injected in young 
persons, than in individuals advanced in life ; and there are even parts, 
in which they cannot be demonstrated, unless in very young subjects. In 
fact, we find in the first periods of life some organs, which are then desti- 
tute of vessels, and in the place of which there are developed afterwards 
others, which possess vessels, thus the cartilages are replaced by 
bones. But this peculiarity disappears when compared with the enor- 
mous development of vessels in all other parts. This abundance of 
vessels is to be ascribed to the great necessity for them, since the num- 
ber of the organs augments continually, they constantly require new 
nutritious fluids. Hence the caliber of the vessels is in direct ratio to 
the volume of the different parts of the same system. 

These observations are true, especially in regard to the arteries, but 
are less applicable to the veins ; for these are scarcely larger at the 
first than at subsequent periods, and at most have a caliber only equal 
to that of the arteries. 

The specific gravity, both of the veins and arteries, is less in young 
men than in old persons ; the vessels are then denser during the latter 



110 GENERAL ANATOMT. 

periods of life. In other respects, the difference is trifling ; it is more 
perceptible in the arteries than in the veins. 

§ 82. We may consider as sexual differences the greater thickness 
and power of the vascular system in males than in females, which is 
observed equally in its three divisions. The localities are no where 
different. 



B. ARTERIES. 

§ 83. The arteries (arterice)(l) differ from the veins in their exter- 
nal form and situation, and in their texture and properties. 

They are usually narrower, less numerous, more deeply situated, and 
more tortuous than the veins. The branch near the heart is always 
larger than the branches which arise from it. The diameter is very 
constant in the same vessels whenever the parietes do not vary. 
In those places where the arteries divide, the largest branch almost 
always follows the direction of the trunk. Anastomoses are rare 
among the arteries of a large caliber, and in general there are fewer 
anastomoses in the arterial than in the venous system ; nevertheless 
they are more common than is usually supposed. We cannot con- 
sider them as a sign of imperfection in the formation of the arteries, 
and as indicating that they are degraded to a level with the ve- 
nous system, as Walther(2) has said, since in the normal state they 
belong no less to the arterial than to the venous system. They are 
developed to such an extent in this system that the largest trunks may 
be obliterated by ligatures, or in any other manner, and the circulation 
nevertheless continued by the anastomoses, which are dilated. Thus a 
dog, in which the two carotid, the crural, and the axillary arteries were 
successively tied, continued to live. (3) Surgeons at present do not 
hesitate to tie, not only the axillary and crural arteries, but the exter- 
nal iliac,(4) the internal iliac, (5) and the primitive carotid.(6) Even the 

(1) Bassuel, Dissertation hydraulico-anatomique, ou Nouvel aspect de Vinterieur 
des arteres et de leur structure, par rapport au cours du sang: in Mem. pres. de 
math, et de physique, vol. i. p. 23-55, Paris, 1750. — Belmas, Structure des arteres 

leurs proprietes, leurs fonctions et leurs alterations organiques, Strasburg, 1822. 

Ehrmann, Structure des arteres, etc., Strasburg. 1822. 

(2) Physiologic, Vol. ii. § 399. p. 43. 

(3) Dissection of a limb on which the operation for popliteal aneurism had been 
performed by A. Cooper; in the Medi. chirur. trans, of London, vol. ii. p. 259. 

(4) Case of femoral aneurism reaching as high a's Pouparts ligament, cured by 
tying the external iliac artery, by J. Abcrnethy ; in Edin. med. and surg. journal, 
vol. in., p. 46.— Case of inguinal aneurism cured by tying the external iliac artery, 
by VV. Goodlad, same journal, vol. viii., no. 29., p. 32.— An account of the anastomo- 
sis of the arteries at the groin, by A. Cooper, in Med. chirurg. trans'., vol iv p 425 

(5) A case of aneurism of the glutceal artery cured by tying the internal iliac, by 
Stevens ; in the Medico-chirurg. transactions, vol. v., p. 422. 

(6) A. Cooper, A case of aneurism of the carotid artery ; in the Med chirurg 
transact, of London, vol. i., no. 1.— Second case of carotid aneurism; same jour- 
nal, no. 17.— Case of aneurism from a wound in which the left carotid artery was 
tied by A. Macauley ; in Edinburgh Medical and Surg. Journal, vol. x., no 38 p 
178.— A case qf aneurism by anastomis in the orbit, cured by the ligature qf the com- 



OP THE VASCULAR SYSTEM. ARTERIES. Ill 

abdominal aorta has been tied(l) or found obliterated,(2) without 
causing any bad effects. We cannot admit a resemblance between 
the venous and arterial systems, except when extraordinary anasto- 
moses are formed between the arteries. 

The arterial is more symmetrical than the venous system in some 
parts, and less so in others. Thus the two spermatic arteries arise from 
the aorta, while of the two corresponding veins the right comes from 
the vena cava, and the left from the renal vein. On the contrary, the right 
subclavian and right carotid arteries have a common trunk, and those 
on the left side have separate trunks, while the jugular and subcla- 
vian veins unite on each side in a single trunk. 

§ 84. The arteries are usually considered more constant in their distri- 
bution than the veins,(3) but we think wrongly. If the veins offer 
greater varieties in their branches, twigs, and secondary trunks, the dif- 
ference is only apparent ; it is because these vessels are more nume- 
rous and larger. In those parts of the system where the arteries equal 
the veins in number, the number of their anomalies is the same. 
In fact, every artery, even the origin of the aorta, is sometimes di- 
vided ; the three large vessels which arise from its arch, present, at least, 
nine or ten varieties, in relation solely to their origin. On the contrary, 
we know only one anomaly of the vena cava superior, where the right 
and left trunks were not united, which, in fact, corresponds solely to the 
division of the aorta at its base, but which we are obliged to compare 
also with the other anomalies of the large trunks, arising from its arch, 
since the vein offers no other. But how common are anomalies in the 
arch of the aorta ! and how uncommon is a division of the vena cava 
descendens ! 

The arrangement of the renal vessels has been adduced as a remark- 
able exception. On the contrary, these furnish the strongest argu- 
ment in favor of the rule just established. (4) In fact, the renal- veins 
vary less frequently than the arteries. 

mon carotid artery ; in Med. chirurg. trans., vol. ii., no. 1. — Finally, Valsalva had 
already tied without inconvenience both carotids on dogs, (Morgagni, Ess. an. med., 
xiii. a. 30). Baillie and Hunter had also advised this operation, when it is indicated, 
( Trans, of a society for the improvement of med. and surg. knowledge, vol. i., p. 125.) 
and Cooper had performed it, but unsuccessfully, although he failed from accidental 
circumstances. (Med. chirurg. trans., vol. i., no. 1.) 

(1) A. Cooper, loc. cit., vol. ii., p. 260. 

(2) Case of obstructed aorta, by R. Graham ; in Med. chirurg. trans., vol. v., p. 
287. 

(3) "I have found many more varieties in the division of the veins, the origins and 
number of their branches, than in the arteries." Haller, De fabr., vol. i. p. 255. — The 
branches of the arteries are generally more constant than the unions of those of the 
veins. Scemmerring, Gefaesslehre, p. 77. — Walther even asserts that the greater con- 
stancy of the course of the arteries proves they are the most noble vessels (Loc. cit. 
vol. ii. § 404.) Bichat has been more exact in saying the arrangement of the 
branches and twigs in the veins is at least as variable as in the arteries. 

(4) Haller, El. phys. vol. iii. p. 260. The renal arteries vary more than any, and 
even more than their accompanying veins, p. 266. " The form of the renal veins ia 
much more simple and constant, than that of the arteries." The renal veins vary less 
than the arteries : Scemmerring, loc. cit. p. 419. Voigtel was, then, mistaken in say- 
ing (Path, Anal. vol. i. 6. 480.) their anomalies equalled those of the arteries. 



112 GENERAL ANATOMY. 

In the extremities, the veins always follow the same course ; and 
although we have often seen the brachial artery divided much higher 
than usual, the arrangement of the corresponding veins was normal 
among all the anomalies of the arteries, while variations in the venous 
trunks are rarely found, unless there are corresponding anomalies in 
thearteries.(l) 

§ 85. The internal structure of the arteries presents, also, several pe- 
culiarities. (2) 

The internal membrane is much thicker, less transparent, harder, 
and more brittle, than in other parts of the vascular system. It is not 
very elastic, and is very solid. In dogs, the other membranes have 
been raised, and, although in several instances the adjacent parts did 
not protect the arteries, still it was neither torn nor distended. (3) This 
membrane differs also in different parts of the arterial . system. It is 
thickest in the left ventricle, less thick in the aorta, and thinnest in the 
pulmonary artery. In the arteries themselves, it seems to be almost uni- 
formly thick every where, although it is thicker in the aorta than in 
the other branches. It is smooth in almost the whole extent of the 
arterial tree, and is not larger than the external membrane. In the 
places only where the great trunks arise from the heart, it forms three 
valves, by expanding and folding on itself. These valves, called sigmoid, 
or semilunar (valvules sigmoidetz seu semilunares) from their semicircu- 
lar form, are attached by their inferior edges to the circumference of the 
arterial orifice : their upper edge, which is loose, forms two fissures,, 
which unite in a central process of a cartilaginous nature, called the 
tubercle (nodulus.) These valves, and the portions of the arteries which 
correspond to them, form sacs closed towards the heart, which open out- 
ward. The parts of the circumference of the vessels which correspond to 
them, are dilated, and project outwardly ; while within, are corres- 
ponding 'hollows, called sinuses. The valves and the tubercles of the 
pulmonary artery, like the other portions of its internal membrane, are 
thinner than in the aorta. But in both vessels, these folds prevent the 
reflux of blood to the ventricles ; for when the fluid takes a direction 
contrary to that which it ought to follow regularly, they leave the pa- 
rietes of the artery, approach its axis, and join so that their edges touch. 
The tubercles fill up the void which may be left between them. • 

(1) For particulars on this subject see J. F. Meckel, Ueber den Berlavf der arte- 
rien und venen. In Deutschen Archiv.f. die Physiol. 1815. vol. i. No. 2. p. 285. 

(2) Ludwio-, Dc arteriarum tunicis, Leips. 1739. rec. in Haller's coll. diss, vol.'iv. 
No. 1.— A. Monro's Remarks on the coats of arteries, their diseases, and particularly 
on the formation of aneurism. In med. essays and observ. of a society in Edinburgh 
vol. ii.— De Lasonne, Sur la structure des arteres, in Mem. dc Vac. des sc. 1756. p! 
166-210.— Mondini, Dc artcriafium tunicis : in Opusculi scicntifici, Bologna, 1817! 
Beclard, Sur les blessures des arteres ; in the Mem. de la soc. med. d' emulation vol' 
viii. Paris, 1817. ' 

(3) Home, An account of Mr. Hunter's method of performing the operation for the 
cure of popliteal aneurysm. In Transact, of the society for the improvement of med 
and surg. knowledge, vol. i. No. ix. p. 144-145. 



op the vascular system, arteries. 113 

§86. The internal membrane of the arteries, and of the arterial portion 
of the heart, in the system of red blood, has a great tendency to ossify. ( 1 ) 
This tendency is strongly seen in the arteries, although it is usually 
developed at an advanced age ; it is then so frequent, that, in 
some countries, after the 60th year,(2) or even, as Stevens says,(3) 
after the 30th, we find the arteries ossified more commonly than unos- 
sified. Bichat says, of ten subjects, there were, at least, saven which 
presented the osseous incrustations, after the 60th year.(4) Cooper is 
not then altogether wrong, in regarding this degeneration as a normal 
state, and in calling it morbid only during youth. (5) Nevertheless, it 
is not an inseparable attribute of advanced age, for we have found no 
traces of it in very aged persons, whom we have dissected expressly 
for this purpose. Perhaps, in this respect, differences exist which may 
be referred to the climate, or manner of living. Ossification is ex- 
tremely rare in the arterial portion of the system of black blood. We 
have never met with it, and we know of but few examples cited by 
authors, except those cases where the valves of the pulmonary artery 
have been found ossified, and adherent even at an early age, — circum- 
stances which contribute powerfully to aggravate cyanopathia. 

§ 87. The fibrous membrane of the arterial system, is firm, hard, dry, 
somewhat elastic, yellowish red, and evidently formed of transverse 
fibres, or to speak more precisely, of fibres a little oblique. These fibres 
form several layers, rarely separable from each other, but which unite 
differently together, as do also the fibres of each layer, so that we can, 
at least in that respect, consider them as so many distinct tunics, since 
their structure is absolutely the same, and their number depends on the 
greater or less attention used to separate them. This membrane is 
commonly known as the muscular tunic, (tunica carnea,) from its fibrous 
structure and reddish color ; but its fibres differ from muscular fibres, by 
their greater elasticity, firmness, fragility, dryness, flatness, and finally 
by the entire want of mucous tissue in their interstices. (6) 

This membrane is the thickest of the arterial tunics, and on it the 
great force of the arteries principally depends. Its internal layers are 
more solid and closer than the external. Its absolute thickness dimi- 
nishes much, as its distance from the heart increases. It is also much 

(1) This inner coat never ossifies: ossification of the arteries depends on an accu- 
mulation of calcareous salt in the cellular tissue, which unites their internal to their 
fibrous tunic : hence these layers can be easily insulated frwn the tunics between 
which they are deposited, and ought to be regarded rather as calculous concretions 
than as real accidental bones. F. T. _ 

(2) Baillie, Of uncommon appearances of diseased blood-vessels ; in the rransac. 
of a society for'thc improv. of mcd. and surg. knowledge, vol. i. no. 8. p. 133. 

(3) In Med. Chirurg, Transact, vol. vi. p. 433. 

(4) Bichat, General Anatomy, vol. i. p. 314. 

(5) Philos. Transact, no. 299. p. 1970. 

(6) Hence a separate tissue has been made of this fibre called the clastic tissue ; 
this tissue, as it is represented, exists also in the parietes of the air passages ; it sur- 
rounds certain excretory ducts ; it forui3 the envelope of the corpus cavcraosum 
and of the spleen, and the yellow ligaments of the vertebra;; it constitutes also the 
posterior cervical ligament in certain animals. See llauff, Dc systemate tela elas- 
tica, Tubingen, 1822. F. T. 

Vol. I. 15 



114 GENERAL ANATOMY. 

greater, and from this, too, the fibrous structure is much more apparent, 
as the arteries themselves are more voluminous, while the piopoitionai 
thicknesss augments in an inverse ratio ; for the panetes become mucn 
stronger, in regard to the orifice and caliber, as the arteries diminisn. 
We also observe that the membrane becomes redder mthe same propor- 
tion, and, if we may judge of it from experiment, proportionally more 
irritable also. 

But the thickness of this membrane differs also considerably, either 
in the different parts of the same artery, or in the different parts of the 
arterial system. In the first respect, it is always more considerable at 
the convexity than at the concavity of the curve of the arteries, and 
also in the angles of their divisions, than in other parts. As regards 
the second point, we must remark : 

1 1st. That the thickness of the arteries within the viscera is propor- 
tionally less than within the muscles, and in the points where these ves- 
sels are loose, than where they adhere to other parts. 

2d. That the arteries of the brain differ much from the others, by 
the thinness of this tunic, which is even so slight, that formerly its ex- 
istence was doubted, but wrongly. ( 1 ) Hence, the cerebral arteries col- 
lapse when they are empty, are more subject than the other arteries to 
break during life, and the blood is more clearly seen through their pa- 
rietes. This layer is much thinner and more extensible in the pulmo- 
nary artery, than in the system of the aorta. 

Some anatomists admit internal longitudinal fibres in the arteries, 
either from applying to man what is observed in animals, or from erro- 
neous observations, or finally, in order to agree with ideas purely theo- 
retical ; these fibres do not exist. 

§ 88. The cellular tunic is very thick, very solid, and perfectly dis- 
tinct from the fibrous. ,It is much more extensible than the internal 
tunic. (2) 

§ 89. The arteries receive some considerable nerves. (3) In general, 
these nerves are more numerous in the arteries of the vascular system 
of red blood, than in the pulmonary arteries. They are also, propor- 
tionally speaking, more numerous and larger in the small than in the 
large arteries. The trunk of the aorta and of the arteries of the neck, 
of the "chest, abdomen, and skull, receive their nerves only from the 
nerves of organic life. They form a very complicated plexus on then- 
surface. The arteries of the extremities, on the contrary, receive 
filaments from the adjacent nerves of animal life. Some pretend there 
are two kinds of the latter : that some of the largest are expanded only 
in the cellular tissue ; that they furnish none to the fibrous membrane, 
inasmuch as they have stillan inconsiderable size; that they are pulpy, 
flat, and soft, at their origins, and that they are insensibly lost in the 
cellular tissue ; they add, that the others are smaller, and penetrate to 

(1) Boerhaave, Prmlect, vol. ii. no. 234. 

(2) J. S. Hebenstreit, De vaginis va$orum, Leipsick, 1740, rcc. in Hallcri coll. dis. 

GoetthT r en b Yik) I,C 363 V ^ 7 arterias vena3 1 w comitantibus; in Syllogc comment* 



OP THE VASCULAR SYSTEM. ARTERIES. 115 

the fibrous tunics of the arteries ; that they are cylindrical, harder, and 
more dense than the preceding ; that the distance between the trunks 
from which they arise and the artery is very small, and that they ex- 
pand in the fibrous tunic, as a thin membrane, on which fibres are dis- 
tinctly seen.(l) Nevertheless we have always seen that the internal, 
or the smallest nerves, are only the branches of the more voluminous, 
and they have never appeared to be rounder or firmer. 

Finally, all the arteries are not accompanied with nerves. (2) We 
find none in the umbilical arteries, and probably those of the interior of 
the cranium are likewise destitute of them. They soon disappear in 
most of the viscera. (3) 

§ 90. The arteries pass, first, into veins, as mentioned before; (§ 76) 
second, into roots of the excretory vessels in glandular organs ; third, 
into exhalent vessels. 

§ 91. The specific gravity of the arteries does not much exceed that 
of water. The relation is about as 106 : 100. They are proportion- 
ally lighter, and less dense, than the veins, being about as 25 : 26. 
Nevertheless, this ratio diminishes with age, and is often in advanced 
life as 140 : 139. This diminution in density is made up by the greater 
thickness of the parietes of the arteries. Nevertheless, the veins 
posssess more resistance, and are more difficult to tear than the ar- 
teries. 

All the arteries have not the same force. Those of the secretory 
organs seem to resist much more than the others. Such, at least, is 
the case with the splenic and renal arteries, where the proportion is as 
13 : 10. 

§ 92. It is not easy to determine, from the phenomena presented by 
the arteries, upon what different forces these phenomena depend. 
However, most of these forces reside in the fibrous and cellular coats. 

The arteries are highly elastic ; hence they remain patulant, after 
ha vino- been divided, and they rebound when compression is removed. 
This elasticity resides especially in the cellular membrane. (4) The two 
inner membranes are more fragile, and hence are more easily ruptured ; 
this is the reason why the two internal tunics of the arteries are torn, 
whenever ligatures are applied to those vessels. 

On the contrary, the arteries are not susceptible of great exteneion, 
nor of great contraction ; they extend and contract in the dimension of 
length more than in that of breadth. We must distinguish from these 
phenomena, the power of the arteries to enlarge, and to lessen. 

(1) Lucae, Quccdam observations anatomicce circa nervos arterias adeuntes et comi- 
tantes, Erfort, 1810. 

(2) Lauth, jun. has, however, followed the threads of the great sympathetic nerve, 
surrounding the vessels of the liver, and losing themselves in their coats, even four 
inches withfn this viscus. — See Lobstein, De nervi symp. hum. fabrica usu et morbis. 
Paris 1823 § 33. — Compare Journ. de lasoc. des sciences, arts et agriculture du de- 
partement du Bas-Rhin. 

(3) Wrisberg, loc. cit. § 30.— Scarpa, Tabul. neurol. ad Must. nerv. card. hist. anat. 
1794. p. 25.— Luca;, loc. cit. p. 28-29. 

(4) We must, however, observe, that the poofs given by the author of the elasticity 
of the arteries refer it to the fibrous, and not to the cellular, coat ; the utmost brittle- 
nesa of the fibrous coat does not prevent it from being elastic. F. T. 



116 GENERAL ANATOMY. 

When the circulation is impeded in a principal vessel, this vessel is 
gradually contracted and reduced to the size of a thread : the colla- 
teral branches dilate in the same proportional) become more tortuous, 
and longer ; but at the same rime their parieles also thicken, but this is 
not always the case. The change then supervening in these latter 
vessels is not confined to simple dilatation. The principal trunk does 
not merely collapse ; it diminishes also in volume, receives less nutri- 
tion, and is destroyed by absorption. Some time after the oblitera- 
tion of a principal vessel, the number of enlarged collateral vessels is 
much greater than at a later period, for in time they diminish, and the 
circulation becomes more similar to what it was in the normal state. 
Further, several weeks are requisite for the dilatation of the collateral 
branches, and this enlargement is greatly hastened by the motions of 
the limb. 

Sometimes there is dilatation rather than increase in mass, as is espe- 
cially the case with the uterine arteries during pregnancy. So, too, 
after death, injections, if pushed with force, distend the arteries very 
much, rendering them tortuous, although they before appeared straight. 
The arteries of old people, particularly those of a large caliber, as the 
aorta and primitive iliacs, are almost always slightly curved, because, 
as they take a less active part in the circulation, the heart sends the 
blood into them with more force, and slightly lengthens them. 

These phenomena result from a mechanical influence. They de- 
pend neither on a force of expansibility, nor on an effort to resist a 
state of expansion ; they are not connected with the life of the artery. 
But it may be asked if the arteries have not, besides, the power of vital 
contraction or of dilatation 1(2) They have not this power, at least 
they are not subject to the will ; still it is incorrect to attribute to elas- 
ticity alone all the phenomena of extension, or of contraction which 
they present. 

This last opinion is that of Haller,(3) Bichat,(4.) and Nysten.(5) 
Bichat, particularly, has supported it with many arguments of which 
the principal are : 

1st. Whatever may be the manner in which the artery is irritated 
whether chemically or mechanically, internally or externally, or even 
by raising its fibres, layer after layer, it gives no sign of organic con- 
traction. Cut longitudinally, it does not turn over on its ed«-es as do 
the irritable canals, the intestines, for instance, in similar* circum- 
stances. 

2d. The artery does not contract when separated from the heart or 
when a portion of it is comprised between two ligatures. 

(1) This subject has been perfectly described by Jones, On the process employed h, 
nature in suppressing the hemorrhage from, divided and punctured artcrie S) Lon,lon 
I808.-Cooper Diss, of a hmb, &c. in Med. Chir. Trans, of London vol Si n 2BT 
An account of the anastomosis of the arteries of the groin, same collection, voi iv.p 424 

(2) Kramp, De m vitah artcnarum, Strasbourg, 1785— "Parry, An cxv inn into 
the pulse and other prop, of arteries, Bath, 1816 : Additional exp. LonfflSlV 

(3) Memotre sur les parties irr. et sens. sect. xi. ' loia ' 

(4) General Anatomy, vol. i. 

penAprt ^° RT? maintained b ? Ma £ e ™*ic. See his Journ. de Physiol, ex- 



OP THE VASCULAR SYSTEM. ARTERIES. 117 

3d. Neither are contractions observed by irritating either the whole 
nervous system, or the proper arterial nerves. Even galvanism doe3 
not produce these phenomena. 

4th. Opium, which destroys the motion of the irritable parts, has 
no effect upon those of the arteries. 

But most physiologists, especially Van Doeveren,(l) Zimmer- 
mann,(2) Verschuir,(3) Soemmerring,(4) and Hunter,(5) profess the 
contrary opinion. It may be objected, generally, to the arguments of 
Bichat, that, in fact, the artery does not always contract under the in- 
fluence of an irritating cause, but the same thing occurs in very irrita- 
ble parts. Also, that the arteries often contract when exposed to the 
action of stimulants. Zimmerman, Lorry, (6) and Verschuir,(7) have 
seen very sensible contractions produced by concentrated mineral 
acids. 

Bichat(8) admits these facts, but says they do not result from con- 
tractibility ; but from a horny hardening, winch is observed as well 
after death as during life, and that the arterial tissue never returns to 
its natural state, after such a contraction. 

But the circumstance alone, that this phenomenon is not constant, 
proves that it depends upon irritability. 

Besides, what is observed in a dead body is not a true contraction, 
but a corrosion,(9) a state entirely different. 

The arteries contract also under other influences than those of che- 
mical agents ; as when irritated by the point of the scalpel. (10) After 
being divided, they sometimes close, so that hemorrhage ceases spon- 
taneously, notwithstanding the impulse of the heart. The im- 
pression of the external air is often sufficient to close an artery ex- 
posed to it, so that its cavity is entirely effaced,(ll) or, at least, is 
much diminished ; and this contraction, which does not every where 
exist uniformly, is always greater than that observed after death, even 
when the vessel contains no blood.(12) Sometimes, also, the arteries, 
when exposed, move with great vivacity, and very differently from the 
usual manner .(13) 

The contraction, dependent on these causes, and which is often very 
considerable, ceases atdeath,( 14) or during life when the irritating cause 
is removed. ( 15) It extends beyond the point acted on by the stimulus. 

(1) Verschuir, he. tit., p. 22. 

(2) Dc irritabilitate, Goettingcn, 1751. 

!3) De vi artcriarum ct venarum irritabili, Groningen, 1766. 
4) Gefcesslehrc, p. 67. 

(5) On the blood, vol. i. 

(6) Vandermonde, Rec. 'period, vol. vi. 

(7) Loc.cit. exp. 1.2. 7.8. 

(8) General Anatomy, vol. i. p. 332. 

!9) Verschuir, Exp. 16. 
10) Ibid. Exp. 8. 14. 18. 

(1 1) HuDter, loc. cil. 

(12) Verschuir, Exp. 8. 

(13) Ibid. Exp. 8. 22. 

(14) Ibid. Exp. 8. 17. 

(15) Ibid. Exp. 18 



118 GENERAL ANATOMY. 

If after death we dilate the artery, which was thus contracted, it col- 
lapses, but much less than during life. 

The electric spark also occasions strong contractions in the arte- 
ries.(l) 

We may also mention against the assertion of Bichat and JNysten, 
that irritation of the nerves, by galvanism(2) or other means, as caus- 
tic alkalies, (3) causes contraction in the arteries. 

There are no arteries, even those detached from the body, which do 
not truly move according to irrefutable proof. (4) In cold blooded ani- 
mals, even when the heart is removed for hours, and even days, we not 
only see the motion of the blood, but a contraction and expansion of the 
arteries. 

Finally, the circumstance that opium produces no effect upon the 
motions of the arteries would prove only that the irritability of these 
vessels is independent of the nervous system, but not that it does not 
exist. 

To all this we must add : 

1. That the arteries do not always and every where exhibit the uni- 
form phenomena of contraction and expansion. Sometimes when a 
limb is paralized, the pulse is deficient in the diseased side, although 
it may be regular in the opposite side. (5) To explain this phenomenon 
we must admit, either that the artery, having lost its contractility, re- 
mains constantly in its greatest state of dilatation, or that the dilata- 
tion is a state no less active than that of contraction ; for in either of 
these states there will be no pulsations. 

On the other side certain arteries sometimes beat with extraordinary 
power. This certainly happens in the large arteries of an inflamed 
part ; and also usually, if not always, in those of a small caliber. This 
phenomenon is observed also in the abdomen, from different causes, 
especially when the activity of the nerves is increased. (6) 

Sometimes the number of the pulsations varies also in the same 
portion of the arterial system. Thus in a patient affected with aneu- 
rism of the pectoral aorta, the pulses were from 100 to 110 in a minute 
in the right arm, and only from 90 to 100 in the left. (7) 

2d. The phenomena of irritability disappear after death in the arte- 
ries, but not immediately. This is proved by the experiments on the 

(\) Bikker and Van den Bos, in Verschuir, loc. cit. p. 29. 

(2) Giulio and Rossi, Diss, de excitabilitate contract, in part muscul. involunt. ope 
animal, electric, in Mem. de Vac. des sc. de Turin, vol. iv. p. 50-52. 

(3) Home has seen the carotid arteries beat for some time and violently in a 
rabbit, after touching' the sympathetic nerve with caustic alkalies. 

(4) Housset in Mem. sur les parties irritab. et sens. vol. ii. p. 404. 

(5) Hoffman, Ueber Empfind. und Reizbark. der Theile, Mayence, 1792, p. 141 — 
Storer, Vicker, and Wells, have observed several similar cases. Storer, Instances of 
theentirewant of pulsation in the arteries of paralytic limbs ; in Transact, of a soc. for 
imp. of med. and surg. knowl., &c, 1812, No. xxxii.— Marshall has witnessed the 
same phenomenon : Case of suppression of urine from stricture succeeded by gan- 
grene of the arm ; in Edinburgh med. and surg. journal, vol. iv. No. 36. p. 449. 

(6) Armiger, Case of Dysphagiaproduced by aneurism of the aorta ; in Med. chir. 
Irans. of London, vol. ii. p. 247. 

(7) Alber'a Ueber Pulsation en Untcrleibe.— Burns, On the principal derangements 
of the heart; On pulsations in the epigastric region. 



OF THE VASCULAR SYSTEM. ARTERIES. 119 

contraction of these vessels according as they had been divided, sooner 
or later. In many experiments of this kind, which have been made on 
the umbilical arteries, it has been remarked in observing the changes 
of their orifices, that they contracted three days after the placenta 
was detached, but that they possessed this power no longer.(l) 

3d. The local application of certain irritants causes the arteries to 
contract, while others excite them to dilate. Ammonia contracts them 
so rapidly that they almost entirely disappear. The hydrochlorate of 
soda, on the contrary, causes them to enlarge their cabber almost a3 
constantly. The rapidity with which this phenomenon takes place, its 
duration, and its power of being repeated, vary much as the subject is 
more or less robust. (2) 

The arteries, besides elasticity, possess, also, irritability. The first 
property predominates in the large, the second in the small vessels. 
It is on account of its elasticity that the artery gapes, that it does 
not collapse, that it remains moderately extended, and that it in- 
creases the force of the blood sent forth by the heart. Irritability 
allows it to contract, to collapse more than when in a moderate 
state of extension, especially after it has been dilated by the efflux of 
the blood. 

The arteries exhibit no sign of sensibifity in their normal state, al- 
though they sometimes evince a fittle when carefully irritated by sti- 
mulants. (3) 

§ 93. The arteries carry the blood from the heart to the organs. 
This function is demonstrated: 

1st. By the swelling and sometimes the rupture of the arteries be- 
tween the heart, and the part where they are tied or compressed. 

2d. By the absence of blood in that part of the vessel situated be- 
tween its periphery and the kgature. 

3d. By the arrangement of the valves at the origins of those trunks 
which arise from the heart. 

§ 94. With a few rare exceptions,(4) the artery moves regularly 
and uninterruptedly through life ; it beats ; it pulsates. Two ques- 
tions are now presented : what change does the artery experience in 
pulsating % how is this change produced 1 

The first problem has been resolved in several different ways. Some 
physiologists admit that the dilatation of the arteries is necessary from 
the afflux of the blood, which the heart sends forth, and which is adied 
to that they already contain ; for, according to them, the arterial sys- 
tem is always full of blood. Others, on the contrary, adducing the 
small quantity of blood sent forth by the heart, which is not sufficient 
to dilate the arteries sensibly, pretend that the pulses are caused only 
by the displacement of the vessels. These two opinions should be 
united, for it is very probable that the same quantity of blood which 



(1) 

(2) 



Hunier, loc. cit. p. 256-7. 

Thomson's Lectures on Inflammation, Edinburgh, 1813, p. 75-89. 

(3) Verschuir, Exp. 12. ,«.,„■.« 

(4) See a case of thia kind in the Mem. de Vac. des sc. dc Parts, 1748 : Hist. p. 87, 



120 GENERAL ANATOMY. 

supports the arterial system should produce in it a marked dilatation also. 
Nevertheless, numerous observations made by us on the arteries of the 
umbilical cord lead us to think that the displacement contributes more 
than dilatation to produce the pulses ; in fact, we have always found 
the displacement very considerable, while the dilatation is scarcely per- 
ceptible. 

The solution of the first question contains also that of the second, 
since it results from it, that the capacity of the arteries changes very 
little in their pulsations : the principal cause of the pulses, and hence 
of the circulation of the blood, is the contraction of the ventricles of the 
heart, which pushes forward into the arterial system a considerable 
quantity of blood. The artery remains passive ; it acts only at the 
second time, during which we see no motion, or at least but very little: 
it is then that it slightly contracts on itself. This theory is founded 
on the following facts : 

1st. The contraction of the ventricles is cotemporary with the dila- 
tation and displacement of the arteries. 

2d. The arteries beat regularly, even when diseased; as, for instance, 
when ossified ; and when irregularities are observed, they take place 
because a morbid affection renders the dilatation, or the displacement of 
the vessel, more difficult. 

3d. The arteries beat even after death when they communicate with 
the heart of a living animal ; and any flexible tube whatever will pre- 
sent the same phenomenon. 

4th. The blood issues most forcibly from the wound of an artery 
during the contraction of the heart. 

§ 95. Nevertheless the arteries concur also, though feebly, by their 
vital contractions, to push the blood forward ; as is proved : 

1st. By the continual flowing of the blood from a wound in an arte- 
ry, although it is more abundant during the contractions of the heart, 
than between them. 

2d. By the circulation of this fluid in acephalous monsters which 
have no heart. 

3d. By its motion and the alternate dilatation and contraction ob- 
served in animals which have no heart.(l) 

§ 96. We may consider as sexual differences the greater thickness 
of the tunics in the male, which is to those of the female about as 
11 : 10 ; a greater density and specific gravity, which is as 154 : 150 ; 
and, finally, their greater force, which is as 13 : 10. The narrow- 

(1) For the part taken by the heart and arteries in the motion of the blood, we refer, 
m addition to the works of Harvey, Haller, Spallanzani, Scemmerring, and Bichat, to 
Prochaska, Controversial physiological, quai vires cordis et motum sanguinisper vasa 
animalia concernunt ; in Opp. rain. anat. arg., Vienna, p. 1-58. This author thinks 
the arteries influence the circulation.— Araldi, Delia forza, c delV influsso del cuore 
sul circolo del sangue ; in Mem. dclle societa italiana, Modena, 1804, vol. xi. p. 342- 
383., vol. xv. p. 2. 1810, p. 166-196. These are researches on the capacity of the force 
of the heart, tending to determine the extent of its influence on the vascular system.— 
T. Young, On the functions of the heart and arteries; in the Phil, transact, of 
Landon, 1809. This author attributes the circulation to the action of the heart alone. 



OF THE VASCULAR SYSTEM. VEINS. 121 

ness of these vessels, compared to the veins, which, in the male, is 
greater than in the female, must be referred to the same. 

§ 97. The arteries are much larger, more numerous, and softer, the 
younger the organism is, except in some points, such as the arch of 
the aorta, and the trunk of this vessel generally, where the force of the 
blood, in advanced age, causes an inverse arrangement ; that is an 
enlargement and thinness. After the middle of life, they become brittle 
and lose their elasticity in a greater or less degree. Their internal mem- 
brane differs most at different periods of life ; for it is frequently ossified 
(§ 86.) Ihe number of the nutritious vessels, and of the nerves 
especially of those filaments which go to the fibrous membrane! 
diminishes by age.(l) 

C OF THE VEINS. 

§ 98. The veins {vena) (2) differ very much from the arteries in 
tneir internal and external arrangement. 

As regards their external arrangement, they offer the following dif- 
ferences as to their capacity, number, situation, direction, the relation of 
the trunks to the branches, and their anastomoses. 

The veins are more numerous andlarger than the arteries They usu- 
ally accompany the arteries, and are even intimately united with them 
But besides the veins termed deep-seated, there are others also which 
arise from the capillaries in several parts of the body, proceed to the sur- 
face, and run immediately under the skin ; hence they are called cuta* 
neous veins. The latter form considerable trunks, sometimes even larger 
than the deep-seated veins, and correspond to no artery. They are seen 
particularly in the extremities. Farther, the deep seated veins which 
accompany the arteries are almost always double, although often of 
small caliber. Hence the capacity of the venous system evidently 
much exceeds that of the arterial system. 

The difference is not equally great every where. In general it is 
much more marked in the vessels of the secretory organs than in others. 
Nevertheless we must not believe it as considerable as it seems after 
death ; because then the blood accumulates in the venous system from 
the inaction of the lungs, and continues to be propelled there by the 
arteries long after they receive none ; and, finally, because the veins 
are very dilatable. 

In some parts of the body, the number of the veins only equals that 
of the arteries, as in the stomach, intestinal canal, spleen, kidneys, tes- 
ticles, and ovaries. 

In other parts a single vein corresponds to two arteries, as in the 
penis, clitoris, gall-bladder, and umbilical cord. Still, even then the 
single veins are always larger than the several arteries whose blood 
they carry. 

(1) Lucse, loc. cit. p.*32. 

(2) Marx, Diatribe anatomico-physiologica de struciurd atone vita, venarum, Carl- 
eruhe, 1819. ' 

Vol. I. 16 



122 GENERAL ANATOMY. 

§ 99. The veins generally accompany the arteries. They issue from 
the organs at the same point as where the arteries enter, as is seen in 
the lungs, kidneys, muscles, intestinal canal, spleen, &c. But besides 
the superficial veins which exist in several parts, as we have stated 
above, independently of the deep veins, the arteries, and veins of cer- 
tain organs, proceed entirely distinct from each other, and enter or 
emerge from different points. The fiver and nervous system, especially 
the brain, furnish instances of this arrangement. The azygos veins 
have no corresponding arteries, unless they are considered as a compli- 
ment to the venae cavse, which is more admissible as they follow the 
aorta. Besides, this view of the subject appears well founded ; for it 
is certain that the general type is strictly followed in the largest trunks 
of the two systems — the aorta and the vena cava. The right and 
left azygos veins, which are situated on each side near the aorta, cor- 
respond to those deep and sometimes very small venous trunks which 
immediately accompany the arteries, while the vena cava represents 
the larger superficial trunks. 

§100. The veins are, in general, more external and less concealed 
than the arteries. We mention, in support of this proposition, the large 
subcutaneous veins which carry back most of the blood of the limbs, 
and also the situation of the deep veins which are-placed at the side, 
and over the. arteries they accompany, as the renal veins ; and the ar- 
rangement of the veins of the brain, which, instead of rising from the 
base of the skull like the arteries, are, for the most part, united at its 
arch, so that they are still more exposed to injuries from external 
agents, as in children they are not in many places protected by bones. ' 

The number of parts where the arteries are nearer the surface than 
the veins, is very small ; in the pelvis, however, the iliac veins are 
situated more internally and farther backward than their correspond- 
ing arteries. When this arrangement exists, it has no effect on the 
security which they ought to have; for the situation and volume of the 
vessel is such, that every wound which would extend to the region it 
occupies would of itself endanger the life of the subject. 

§ 101. The direction of the veins is straighter than that of the arteries; 
this facilitates the course of the blood within them very much. They 
ramify like the arteries, except that the relation between the branches 
and trunk is not so constant, that is, that the branches appear nar- 
rower : but this depends principally on the greater dilatabUity of the 
veins which allows the least cause to distend their small branches in 
one point or another so much, that their diameters equal and even sur- 
pass that of the trunk from whence they arise. The branches are 
broader than the trunk especially when the blood is forced to proceed 
a long period against its own gravity, as when we stand or when the 
arms hang down a long time. 

§ 102. In general, a constant law of the arrangement of the veins 
is, that the branches and twigs are larger in proportion to the trunks 
than in the arterial system; so, too, the veins of one part, and even 
those of the whole body, never unite in so small a number of common 



OF THE VASCULA.lt SYSTEM. VEINS. 123 

trunks as that of the principal vessels which give rise to the arteries. The 
aorta and pulmonary artery come from their respective ventricles. On 
the contrary, the veins of the body arrive at their auricle in three 
trunks, the superior and inferior vena cava, and the large cardiac vein. 
The first receives a large vein just before entering the right auricle, the 
azygos. The pulmonary veins arrive at the left auricle four, sometimes 
five, and even six in number. At the side of one brachial artery we find 
four large venous trunks. The character of the veins then is to rami- 
fy, and that of the arteries to concentrate themselves. 

§ 103. The veins present a character opposite to the arteries in re- 
gard to their anastomoses ; these are more numerous and more gene- 
ral in the venous system : nevertheless, there is no contrast between 
these two laws, as the second is a consequent of the first. 

In fact, the less degree of concentration in the veins renders the 
anastomoses more necessary, at least in part, in order to replace to a 
certain extent the common trunks which are not formed by the large 
branches. 

Not only are the communications between the small branches as nu- 
merous as in the arterial system, but the large branches and the large 
trunks anastomose together more frequently than in that system. We 
see a remarkable instance of this in the subcutaneous veins of the ex- 
tremities. But this law of the superficial veins is subordinate to another 
of a higher order : that the anastomoses increase in number wherever 
the course of the blood in the veins is more difficult, from a want of im- 
pulse and of powers which favor it. Hence their frequency in the sub- 
cutaneous veins of the limbs ; in the spermatic veins, which are narrow, 
and very straight ; and finally in the veins of the pelvis which are ex- 
posed to compression from so many different causes, and which fre- 
quently anastomose, to form a network so complicated, that it is diffi- 
cult to follow the direction of the vessels correctly. 

The number of the anastomoses in the venous system is also increased 
by this circumstance, that in many parts the veins form two distinct 
layers, the one superficial, the other deep. These two layers constantly 
communicate, as is seen in all the superficial veins of the limbs of the 
neck and head on the one hand, and the deep veins of the neck and 
arm, and the sinuses of the dura mater, on the other. 

The great trunks of the venous system of the body communicate by 
a large anastomosis, the azygos vein, which arises directly from the 
vena cava inferior, or from some one of its ramifications, and empties 
itself into the vena cava superior. 

This arrangement explains how the circulation continues, although 
it may be impeded by some very considerable obstacles ; as, for in- 
stance, when the principal veins of the limbs are entirely obliterated, 
or when the vena cava inferior is compressed in its course behind the 
liver by the swelling of this gland. 

§ 104. The venous system is more complex than the arterial, as re- 
gards its extent. The arterial system ramifies incessantly and uni- 
formly after leaving the heart ; both the aorta and the pulmonary ar- 



124 GENERAL ANATOMY. 

tery represent each a single tree. But the venous system of the 
body embraces in the peritoneal cavity a second tree, that of the vena 
porta, which communicates as usual with the arteries of the abdominal 
viscera ; but which, instead of carrying its blood directly to the vena 
cava inferior, ramifies in an opposite direction in the liver, and thus re- 
presents two trees, one' of which, the venous portion, carries the blood 
of the branches to the middle trunk, while the other, the arterial part, 
distributes it from this part to the liver, from whence it passes into the 
hepatic vein, to arrive finally at the inferior vena cava. 

§ 105. The principal differences in the texture of the veins are the 
following. 

The internal membrane is thinner, more delicate, but more extensi- 
ble, and less fragile, than that of the arteries ; at the same time it does not 
ossify in old age. This alteration of texture is a very rare phenomenon 
in the veins, while it is almost normal in the arteries, of aged persons. 
We improve this opportunity to observe, that in regard to this we should 
compare not only all the carrying vessels of the arterial system, con- 
sidered as a whole, but also the pulmonary vein, the veins of the body, 
the pulmonary artery, and the internal membrane of the right ventricle, 
should be opposed to the left portion of the heart and the system of the 
aorta ; so that there is only the arterial portion of the system of red 
blood which has a marked tendency to ossify. The truth of this law 
becomes still more striking when we know the opening between the 
auricle and ventricle is the bmit of ossification on the internal face of 
the left portion of the heart; and we seldom observe ossifications in the 
auricle, while they are very common in the ventricle. 

§ 106. The internal membrane of the veins differs also very much 
from that of the arteries in its purely physical arrangement ; for the 
valves (§ 69) are generally very common in the veins, while in the ar- 
terial system they are met with in only two parts.(l) The chief points 
in their history regard their form, direction, number, situation, and 
size. 

1st. The form of the valves of the veins is that which valves gene- 
rally possess. They are slightly parabolical ; one of their edges is semi- 
circular and attached — the other is loose and straight, or little fissured ; 
both are slightly turned over. The valves and those parts of the cir- 
cumference of the veins to which their similunar edges are attached 
form sacs, the diameter of which is a little larger than that of the ad- 
jacent part of the vessel. 

2d. Their direction is opposite to that of the valves of the arteries. 
Their loose edges, and the bases of their sacs are turned from the heart' 
so that the blood which runs from this organ distends them, and that 
which flows towards the heart presses them against the parietes of 
the vein. 

(1) Meibomius, Devalvulis seumembranulis vasorum, carumquc structvra et vviu 
Helmstadt, 1682, rec. in Haller's, Coll. Diss. vol. ii.-Th. Kemper, teZvucZm 
*n corp. hum. naturajabrica et usu mechanico, Jena, 1683, rec. ibid. vuvuiarum 



OF THE VASCULAR SYSTEM. VEINS. 125 

Their number offers several points for consideration. 

a. They do not exist every where. There are none in the system of 
the vena porta, of the pulmonary veins,* the umbilical vein, the trunk 
of the vena cava inferior, in the veins of the brain, of the vertebrae, 
of the spinal marrow, of the heart, of the kidnej^s, and of the womb. 
Still these veins make the transition to those which possess many 
valves, since they are sometimes found in them but very rarely, and 
are always incomplete. The sexes seem to differ also in this respect ; 
at least the spermatic veins of the female have no valves, while they 
exist in those of the male. There are none, or but few, in the anasto- 
mosing branches. Hence while there are many in the median vein of 
the arm, there are very few in the azygos vein. 

b. Even in those parts of the venous system which possess them, 
the number of valves varies. Generally speaking, this number in- 
creases in the inverse ratio of the cahber of the vessels. Nevertheless 
the valves disappear entirely in the small veins ; more are also found 
in the superficial, than in the deep seated veins. 

c. The number of valves varies also in this point of view, that the 
number of these folds which close the orifices of the vessels is not every 
where the same. These valves are usually arranged in pairs, as is 
seen principally in the large trunks and large branches. Sometimes 
also they are insulated ; this last arrangement takes place in the veins 
less than a line in diameter. Still we find also single valves in the 
large veins ; as, for instance, at the opening of the vena cava inferior, 
and of the great cardiac vein into the right auricle. These single valves 
are proportionally larger than the others. 

Sometimes also three, or even four and five valves are found where 
usually only two exist, but this state of things is rare, and is not con- 
stant. 

4th. With regard to the position of the valves, we may say they 
are generally found in those parts where a subordinate vein unites 
with a larger one ; sometimes there are none in these points, while we 
see them in others where no such union exists. 

5th. The valves vary in size. They generally close the mouth of 
the vessel entirely. This closure is more perfect when there are two 
or three ; but sometimes they are insufficient to shut up the passage 
entirely. Thus, in certain places we find only a slight projection the 
rudiment of a valve. Besides, particularly in the sinuses of the dura 
mater, there are transverse cords, incontestable marks of valves which 
are also observed mother veins, as, for instance, in the crural veins, (1) 
but not constantly. 

* This assertion has recently b6en contradicted by Professor Mayer, {Zeitschrift 
der Physiologie, vol. iii. p. 155,) although hitherto admitted by all systematic wri- 
ters on anatomy. Professor M. states, that the valves are large and numerous in the 
pulmonary veins, and always occur where a venous branch joins the larger trunks 
at an acute angle; and the more acute the angle, the more marked is the valve. 
Where the branches join at a right angle, however, no valve exists, as is the case in 
the other parts of the venous system. Hence the valves aTe fewer in the pulmonary 
than in other veins, because the ramifications of the pulmonary veins take place 
chiefly at right angles. 

(1) Haller, De fabr. vol. i. p. 265. 



126 GENERAL ANATOMY. 

We must here speak of the differences presented by the valves as 
respects their integrity. They are commonly entire, but sometimes 
they seem to be torn, especially on their loose edge. Doubtless this 
arrangement often results from a primitive formation, which has con- 
tinued ; but it may be consecutive also, and may then arise from com- 
pression or any other cause, as, during life, the valve at the orifice of 
the vena cava inferior, which is at first entire, is frequently changed 
into a network, or reduced to simple filaments, or disappears entirely. 
The valve placed at the orifice of the large cardiac vein often presents 
the same phenomenon. But these valves are precisely those most 
exposed from their situation to the influence of mechanical causes, 
and before birth they are always entire. When the reticulation of 
the valves is congenital, it marks the transition of the simple trans- 
verse filaments to real valves. 

§ 107. The fibrous membrane of the veins differs also from that of 
the arteries. 

1st. It is thinner. The difference between the two systems in this 
respect, is still greater than that mentioned when speaking of the 
internal tunic ; since distinguished anatomists, as Vesalius, have not 
been able to see this fibrous membrane. 

2d. Its fibres are less closely connected, and hence this layer is 
less dense and less compact. 

3d. It does not exist in every part of the venous system. While in 
the arterial system it becomes even proportionally thicker in the small 
ramifications, it is only visible in the large branches of the veins. 
There is, however, between the large branches and trunks of the 
veins the same relation as respects the thickness of this membrane, 
compared to their caliber, as in the arteries. 

4th. The fibrous membrane of the veins offers also other differ- 
ences in regard to its thickness and even its existence. 

o. It is always proportionally thicker in the system of the vena 
cava inferior, than in that of the vena cava superior ; a remarkable 
difference which evidently coincides with the obstacle opposed by the 
weight of the blood to its progress in the former system of vessels. 

6. It is also stronger in the subcutaneous than in the profound 
veins, which depends on the same cause ; for the course of the blood 
not being favored in the former as it is in the latter by the pulsations 
of the adjacent arteries, the structure of the vessels should compen- 
sate for this unfavorable circumstance. 

c. The fibrous membrane is evidently deficient in several parts, 
especially in the venous trunks," situated between the two layers of the 
dura mater, that is, in the meningcean siauses. Most anatomists even 
suppose that there is no venous membrane in those parts, and that the 
blood runs directly on the dura mater. But Bichat(l) has proved 
this opinion to be false. .In examining attentively the interior of the 
triangular space formed by the separation of the two layers of the 

(1) General Anatomy, vol. i. p. 402. 



OF THE VASCULAR SYSTEM. VEINS. 127 

dura mater, we discover a rounded canal, formed by the internal mem- 
brane of the veins. Now this canal continues on one side with the 
internal membrane of the cerebral veins which communicate with the 
smuses of the dura mater, and on the other with that of the internal 
jugular vein, into winch these sinuses open. The dura mater which 
slightly resembles the middle membranes of the vessels, here replaces 
it. As, however, the dura mater has no contractility, it would seem 
that the purpose of this absence of the fibrous membrane is to retard 
the course of the blood. 

The veins which open into the sinuses of the dura mater, are all 
well provided with a fibrous membrane, but it is thinner in proportion 
there, than in the other veins of an equal volume. 

5th. The veins differ also from the arteries in the direction of their 
fibres. 

We have ascertained by the most minute dissections, that these 
fibres are all longitudinal, and there are none which are circular.(l) 
This difference between the arrangement of the arterial and venous 
fibres is remarkable, inasmuch as the two layers of longitudinal 
and transverse fibres which are observed in the whole extent of the 
intestinal canal, reappear also in the vascular system, which is but a 
development of the intestinal tube ; but the membranes are separated 
and distributed each to one of the principal portions of the vascular 
system. This analogy is strengthened, as the external layer of the 
fibres of the intestinal canal is composed of longitudinal fibres, and 
the internal of oblique fibres, as the external is always feebler than 
the internal, and as the first is deficient, or at least is not very appa- 
rent in several parts, either of the circumference or of the length of 
the intestinal canal. Thus the longitudinal fibres are united in three 
distinct bands in the large intestine, and in the small intestine they 
are so thin, that, in many parts, they are indistinctly seen. 

6th. The fibres of the venous membrane are redder, softer, more 
extensible, and less brittle than those of the arterial tunic. 

7th. Their arrangement and their existence are more liable to varia- 
tions than those of the arterial fibres, for they are very well developed 
in certain subjects, and are scarcely visible in others : a new point of 
relation between the fibrous membrane of the vessels and that of the 
intestinal canal. 

§ 108. The cellular membrane of the veins is also thinner, less 
dense, and less solid than that of the arteries. Prolongations proceed 
from it to the fibrous membrane, which are not observed in the arteries : 
these extend even to the inner membrane. The veins of the brain 
have none. 

§ 1 09. The veins receive fewer blood-vessels than the arteries, which 
is undoubtedly because they are thinner. 

Their nerves, both those which come from the system of animal 
and from that of organic life, are equally less numerous than those of 

(1) Bichat said correctly, "There are no circular fibres in the veins."— p. 403. 



128 GENERAL ANATOMY. 

the arteries. This relation certainly exists between the system of the 
vena cava and that of the aorta. 

§110. The veins are much more extensible(l) than the arteries. 
The latter tear when slightly distended; the veins resist much more, 
and often dilate considerably when the course of the blood is impeded 
by an obstacle. They are then less elastic than the arteries. 

They are equally susceptible of vital contractions, although these 
have not been observed in every experiment. 

The large trunks which possess very apparent fibres, are particularly 
irritable. 

§ 111. The veins return the blood to the heart, and change neither 
in their diameter nor in their situation. They do not pulsate except 
in some rare and extraordinary cases. 

The facts which prove that they really perform the above men- 
tioned function are, 

1. When tied, they swell between the surface of the body and the 
part to which the ligature is applied, while they are empty between 
this point and the heart. When these phenomena do not take place, 
it is on account of their anastomoses. 

2. The direction of the valves. 

3. In microscopical observations, the blood has been seen proceeding 
within them, from the surface of the body towards the heart. 



D. LYMPHATIC VESSELS. 

§ 112. The lymphatic vesels (vassa lymphatica) (2) form a system, 
which differs from that of the veins by the nature of the fluid it carries, 

(1) The phenomena of erectility depend principally on the extensibility of the 
veins. Some have formed a special tissue of the corpora cavernosa of the penis 
and clitoris. This has been termed the erectile tissue, and to it have been referred 
the papilla?, raamms, &c. Degraaf, Ruysch, Duverney, Boerhaave, Haller and his 
school considered it as a loose and elastic cellular tissue, forming' cellules, and inter- 
posed between the arteries and the veins. Duverney, Mascagni, Cuvicr, Tiede- 
mann, Ribes, Moreschi, Panizza, and Farnese have demonstrated that it consists 
only in the terminations of the blood vessels, especially the roots of the veins, which 
are very large and extensible, supplied with many nervous filaments. — F. T. 

(2) Although we find traces of a knowledge of the lymphatic system very early, 
and even in the works of Aristotle, (Hist, anitn. lib. iii. c. vi.) the different portions 
of this system have been successively known ; the Swede, Olaus Rudbcck, in 1650, 
discovered the connection of these vessels with the thoracic canal, and the motion of 
the fluid which they contain, (Nova experimenta anat. exhib. ductus hepalis aquosos ct 
vasa glandularum serosa, Westerns, 1653). The structure and distribution of the lym- 
phatics have been particularly studied in England by G. Hunter, (Med. comment. 
London, 1762, vol. i.) Hewson, (Experimental inquiries, vol. ii. London, 1784, vol. iii. 
1777,) and Cruikshank, (The anatomy of the lymphatic vessels of the human body, 
London, 1774); in Germany by Meckel, (Diss, cpist. ad Haller. de vasts lymph, 
elandulisque conglob., Berlin, 1757, in8vo. — Nov. exper. definibus venarum et vas. 
lymph, in ductus visceraque excretoria corp. hum., Berlin, 1772, in 4to.); in Italy, by 
Mascagni, (Vasor. lymph, corp. hum. historia et ichnographia, Sienna, 1787, in fol.) 
Ludwig has collected the principal works on this subject in G. Cruikshank' s und P. 
Mascagni's Geschichte und Beschrcibung der Saeugadern des mcnsclichcn Kasr- 
pers, Leipsick, 1789, 3 vol. in 8 vo.— Werner and Feller, Vasorum lactcorum, atquc 
lymphaticorum anatomica physislogica descriptio, Leipsick, 1786.— Haase, Dc vasi& 



OP THE VASCULAR SYSTEM . LYMPHATICS. 129 

but which ought to be considered an annenda o-a t n *v 

count of the connections between them We W. ^T* ° U ™~ 

et rtt trr^ th r ther ? the ri s ht > ^ h « ■*£ ^ " * 

luni liv.r ,v i ympha " C , S °/ theri S ht half of lhe head and neck, 

eSate S thT^ agm ' "S ° f the risht su P e ™' extremit y i all others 

entTL™ Is ?h» 1 i ' " " 0t Certain but that in m a°. as in differ- 

svstemm tn n ?l, ymphatlC t° f a ™ allcallber °P™ ^o the venous 
system(l) in other parts than the two already mentioned gome 

"he be e KeT h ,fr <£*** "Native L~ ee ™ toTu- 
§ 114. The lymphatic system resembles the venous more than the 

a r al si kt xt aiso mexs i much fr ° m *. aith °^ <»££ £ 

&p™ 2 £ ^ lts anaIo S ies with the venous system, and 
its differences from the artenal system : 

I. In relation to external form, 
othe'r profound^™ SJStGmS ^ tW ° l * m ° ne su P erficial > and the 

tmnt The n T ber ° f branches and ^igs compared with that of the 
trunks, is much greater than in the arterial system 

hr :\ A brancb -. r emote from the heart is not always narrower than the 
branch with which it communicates. 
4th. Their capacity is very variable. 

n l u' rS^ are *?** and more nu merous than the arteries, 
otn. I heir direction is very straight. 

7th Their anastomoses are very numerous, and obey the same laws 
as m the veins. 

But these relations do not establish the identity of the venous and 
lymphatic systems ; for, 

Ssick^m ^fi^f k ' ^--Schrceger, Fragmenla anal, et phys.fakl, 

veins ^W th™°W Tiff P, uLlished ' ^e communication of the lymphatics with the 
mSSrSLl / horacic canal, has been proved by Fo/mmnn, (Anato- 

latter ShM T ,J k' [? S8 ? lSU . rleS '. ( "^«^/V'»M-,Strasburg- ) 1814). The 
rtsl^X ink th * e '^P^ics termmate in three modes : 'those which as capilla 
veins 3n the Ivmn?^ m , the 1 tlssu< ;? of theorgans; those which terminate in the 
onln ,w!h7 *^ 7 P C ^"t', 6 "^ ln th e same manner; finally, those which 
open into the thoracic canal and the large lymphatic vein of the right side FT 



130 GENERAL ANATOMY. 

1st. The distinction of the lymphatics into superficial and deep- 
seated, is more general than in the veins : not only the trunk the head, 
and the extremities, but also all the viscera have superficial and deep- 
seated Ivmphatics. The difference is still greater between these two 
orders of lymphatics, than between the two corresponding orders of 
veins, both as respects number and volume, for the largest and fewest 
lymphatics are not the superficial, but the deep-seated. 

2d. The proportion between the small divisions and the trunks is still 
more advantageous to the former than in the veins ; the concentration 
is still less. In their course, which is often very long, as for example 
in the limbs, the lymphatics of no part of the body unite in several large 
trunks ; but their diameter being exactly the same or nearly so, we 
see them, from the instant they become visible, advancing separately, 
or in great numbers, to the neighborhood of the principal trunk, where 
their number diminishes, although inconsiderably, and where their 
volume augments in the same proportion. 

3d. The branches remote from the heart are often much more nu- 
merous and much larger than those near this central organ ; this ar- 
rangement exists much more frequently in the lymphatics than in the 
venous system. 

4th. Their capacity is much more variable than that of the veins. 
The preceding difference depends on this : hence, too, the reason that 
in living dissections, and sometimes even after death, we find the lym- 
phatic system dilated from space to space, so as to form considerable 
vesicles, which in living animals often entirely disappear. Finally, it is 
for this reason that we cannot fix the exact relation between the trunks 
and their branches, and that the calculations made of the caliber of the 
large thoracic trunks are so very different. 

5th. The lymphatic system is almost as broad as the venous ; but as 
the branches do not unite in trunks, their number is much greater than 
that of the corresponding veins, and each large venous or arterial trunk 
is accompanied with at least ten lymphatics. 

6th. The direction of the lymphatics is in general straight. Still they 
sometimes curve considerably, and even more than the arteries. 

7th. The anastomoses are still more frequent in the lymphatic than in 
the venous system, which accords entirely with their less degree of 
concentration. Even their trunk is completely surrounded with very 
many large anastomosing vessels, which also communicate with it 
extensively, and which are sometimes so voluminous that we can with 
difficulty distinguish a single principal trunk, and are obliged to admit 
an immense network of lymphatics. 

§ 115. The lymphatics are not a continuation of the arteries like 
the veins. They arise independent of them.(l) It has usually 'been 

(1) Although it is certain that the lymphatics are not connected with the arteries 
as with the ve^ we however admit with Lauth jr., (Essaisur les vaUseaut hjmpZ 
sect. 2. p 12.) the existence of lymphatics which arise from the internal surface of 
the artenes, as from all the other surfaces, which is well proved by inflammations 

F. T. 



OF THE VASCULAR SYSTEM. LYMPHATICS. 131 

supposed, since the discovery of this system, that some arteries called 
lymphatic {arteries, lymphaticce) continue with the proper lymphatics, 
in the same manner as the final ramifications of the arteries, which 
also carry red blood, join the roots of the veins ; but this arrangement 
cannot be demonstrated. 

The principal reason alledged is drawn fiom what has been observed 
by several anatomists in different parts of the body, that fluids of all 
kinds, introduced into the arteries, penetrate into the lymphatics. 

But then we always find ruptures and extravasations ; when even the 
final twigs of the arteries should have been injected, they are filled only 
in their trunks or large branches : finally, the phenomenon itself is rare 
when there is no ♦ extravasation, even when the arteries are filled 
more successfully, and the injection reaches the veins through them. 

When there is no rupture, and the arteries are perfectly injected, and 
the veins are at the same time filled, it sometimes happens, that the 
injection passes into the lymphatics ; but its colorless portion pene- 
trates into them, so that we cannot conclude from this there is an unin- 
terrupted communication between the injected lymphatics and the 
arteries, since the colorless fluid is found also out of the vessels, and 
abounds in the part injected. This phenomenon then is better explained 
by saying, that the colorless portion of the injection transudes through 
the arteries, and is absorbed by the lymphatics. 

The following are the principal arguments to prove that the origin 
of the lymphatics is independent of the arteries :(1) 

1st. The circumstances attending the passage of fluids from the arte- 
ries or veins to the lymphatics. 

2d. The phenomena presented by the lymphatic system in regard to 
the substances submitted to its action. The fluid contained in these 
vessels exactly resembles that found at their origin. The lymphatics 
coming from the liver contain a fluid analogous to bile ; those from the 
breasts a milky fluid ; those which arise from parts where blood is 
effused, a liquid resembling blood. The bronchial glands, and often 
even the lymphatics which go to them, are of a blackish blue, like the 
lungs. The color of the spleen is the same as that of the lymphatic 
glands placed near it. If a deleterious substance, as the pus of a ve- 
nereal ulcer, or of a varioloid pustule, or generally of any ulcer what- 
ever, be presented to the action of the lymphatics, those which arise 
from the diseased part inflame, and the glands in which they terminate 
swell. This effect takes place only in the side on which the delete- 
rious substance acts. 

As all these phenomena supervene uniformly when their causes 
exist within the organs, in the cavities of the viscera, or on the surface 
of the body, we have no doubt that the lymphatics arise from the 
substance of the organs, and from their surfaces, particularly from the 

(1) Hunter, Medical commentaries, London, 1762, p. 5.— A. Monro, De venis lym- 
phaticis valvulosis, Berlin, 1757. — Hewson, Exp. inquiries, p. 2., London, 1774, chap, 
ii.— Morgagni, Loc. cit. t sect. 3., De vasorum lymph, origine. 



132 GENERAL ANATOMY. 

cutaneous system, both from the skin properly so called,(l) and from 
the mucous and serous membranes. 

6 116 Our remarks on the external form and on the track of the 
lymphatics, apply to their texture also. Their internal membrane is 
still finer, thinner, and more ' extensible than that of the veins and is 
not subject to ossification. It also forms parabolic valyes,(2) which 
are generally arranged in pairs, but are sometimes insulated, and are 
usually more numerous as the vessels diminish m caliber so that the 
thoracic canal contains fewer than all the others. The distance 
between them is not every where the same : but a general law is, that 
it is much greater in the lymphatics than in the veins. 

§ 117. The fibrous membrane(3) is deficient »ot only, as in the 
veins, in most of this system, but even in the thoracic canal ; at least 
the most attentive observations have not recognized it m man. The 
internal membrane is directly under the cellular tunic, which is thinner 
in proportion to the size of the vessels, than in the other parts of the 
vascular system. 

§118. Besides all these differences the lymphatic system presents 
others which are very considerable. We may mention here the con- 
globate glands, (Glandules lymphaticce, conglobate,) peculiar forma- 
tions which are found in no other part of the vascular system. 

§ 119. These conglobate glands are small round bodies more or less 
oblong, usually a little flattened, of a grayish red color, hard, varying 
much in size, which exist in certain parts of the body, where they are 
about the same in number and volume ; they interrupt the course of 
the lymphatics, are not symmetrical, and have no regularity in their 
arrangement. 

These glands vary considerably and constantly in number, form, 
size, and color. 

1st: Most of these glands are found in the neck and within the pec- 
toral and abdominal cavities, along the sides of the vertebral column, 
and also between the folds of the serous membranes, which retain the 
organs situated in these cavities, and near these same organs, for 
instance, at the roots of the lungs, around the bifurcation of the 
trachea. 

They are very numerous in the face, especially around the mouth. 
There are fewer in the skull. 



(1) Lauth, jun., (Essay on the lymphat. sect. 2, p. 13.) has even demonstrated 
anatomically, that the lymphatics arise from the surface of the skin, having injected 
them to its outer face. — F. T. 

(2) We often find (E. A. Lauth, Essay on the lymphatics, sect. 1, p. 4.) in the 
lymphatic trunks annular valves formed by the union of two valves, which being 
lower than usual, do not close the canal entirely. The same arrangement exists in 
the lymphatics of the different viscera, especially thefee of the tivcr. — P. T. 

(3) Mascagni denies the existence of muscular fibres also in the lymphatics. 
Schreger admits, however, (F'ragm. anat. et phys. fasc. 1, Leipsick, 1791, p. 9.) 
that there are transverse fibres in the thoracic canal of man and the calf. Scem- 
merring also believes they exist in this canal. Rudolphi was unable to find them 
either in man or in the horse.— F. T. 



OF THE VASCULAR SYSTEM. LYMPHATICS, 133 

In the extremities they commence usually at the elbow and knee, 
and are placed around the articulations ; there are fewer, however, in 
those parts than in the axilla and groin. 

Their existence has never been demonstrated within the organs, and 
the proofs of them,which are believed to have been found in those peculiar 
morbid masses, which are developed in these parts, as in the lungs, 
the liver, the spleen, the brain, &c, are insufficient, since these masses 
never present the characters of lymphatic glands ; and examining 
them attentively, we recognize that they are not even glands. The 
conglobate glands exist only in the mucous tissue between the organs. 
We find none in the skull. 

In comparing these glands, as regards their greater or less abun- 
dance in different regions, we arrive at the following results : 

a. They increase in number as they approach the trunks, which 
throws some kght upon their functions. 

6. They are entirely distinct and separate from the proper substance 
of the organs. 

c. They are especially numerous in those parts, where the mucous 
tissue abounds. 

d. They are found in great numbers in those places where foreign 
substances come ; consequently near the lungs and intestinal canal. 

2d. The lymphatic glands vary much in size, in the same, and in 
different regions of the body. The largest exist in the groin, the 
pelvis, around the bronchia, in the mesentery, and in the axilla. But in 
these different places we see them alternately large and small. They 
are rarely more than an inch long, half an inch broad, and three 
or four lines thick. Age certainly affects their size. Is the same 
true of sex ? We cannot think it, since excellent observers contradict 
each other on this point. Hewson says they are proportionally larger 
in the male,(l) while Bichat asserts that they are more evident in the 
female. (2) They are assuredly larger in youth than towards the 
close of life, for, in old age, they much diminish, and in some parts 
often entirely disappear. But do they enlarge much after puberty, as 
Hewson pretends ? Our observations have not determined it. 

3d. Their form depends in some measure on their size. The largest 
are flatter and more oblong, the smaller are rounder, the smallest are 
perfectly round. It is very remarkable that each system of organs is 
subject to the same laws as the whole series of organized bodies ; 
since, in general, also living beings resemble them in every sense, that 
is to say, become rounder as their volume diminishes. 

4th. Their color also varies much. Those found within the pecto- 
ral and abdominal cavities are the brightest ; the subcutaneous glands 
have a deeper tinge ; those placed at the base of the lungs and of the 
trachea are the darkest, and are almost black ; those which are near 
the spleen are also" deeply colored. These differences of shade seem 

(1) Exp. inquir. p. 3 and 50. 

(2) Gen. Anal. vol. ii. p. 113. 



134 GENERAL ANATOMY. 

to depend partly on the influence of the light, and partly also on the 
nature of the fluids within them. Hence the dark color of the sple- 
nic and bronchial glands, the yellow color of those near the liver, and 
the white appearance of those of the mesentery, which are filled with 
chyle. 

§ 120. The general conditions of the structure of the lymphatic 
glands are as follows. At first sight they resemble a homogeneous 
and almost smooth mass. But when the lymphatic vessels which 
enter them are filled, their surface becomes irregular. They receive 
a considerable quantity of blood which is generally conveyed to them 
by several branches which divide within them into very fine twigs. 
They receive branches of nerves, but these are very fine. They are 
not enveloped with a membrane proper and distinct from their sub- 
stance ; their surface is well covered with a dense cellular tissue, but 
this tissue cannot be detached from their substance without destroying 
it. The cellular capsule does not continue insensibly with the surround- 
ing mucous tissue, but is separated from it by well defined limits, 
so that these bodies are very movable in health, and do not become 
fixed and adherent in diseases, except when the cellular tissue which 
surrounds them is inflamed. 

The general phenomena of the connection of the lymphatic vessels 
with their glands, are as follows. At some lines distant from the peri- 
phery of the gland, at the end farthest from the thoracic canal, one 
or several lymphatics, according to its volume, divides into branches 
which enter into it with the blood vessels, and these again separate 
into numerous small vessels ; but towards the other extremity of this 
gland, these ramusculi again unite in a small number of simpler 
trunks, which leave the gland and go forward. These last vessels 
may be considered as the excretory ducts of the lymphatic glands. 

§121, Are there in the lymphatic glands any integral parts besides 
those already mentioned? Many anatomists, namely, Malpighi, 
Mylius, Cruiskshank, Werner, and Feller, admit also proper follicles, 
a species of hollow, rounded, white, and soft cellules, which constitute 
the glands in great part, and in whose parietes the blood vessels are 
distributed, and from whence new lymphatics arise. Some say that 
these cells are arranged uniformly, which is denied by others. Thus 
Werner and Feller pretend that in the glands nearest the intestinal 
canal, there is but a single large central vesicle, from whence the 
vasa afFerentia arise, while the glands situated farther from the intes- 
tine, and those of all the other regions of the body, contain several of 
these cellules. Facts in comparative anatomy also would lead us to 
admit the existence of cells in the lymphatic glands of man for we find 
some very large, for instance, in the lymphatics of the horse and ass. 

But according to other anatomists, particularly Ruysch Albinus 
Gmelin, Hugo, Haase, Meckel, Hewson, and Masflagni, the lymphatic 
glands are only agglomerations of blood-vessels, of lymphatics, and of 
mucous tissue^ The cellular structure of these organs is very impro- 
bable, at least in man. 



OF THE VASCULAR SYSTEM. LYMPHATICS. 135 

Hewson admits, besides the vascular plexuses, small cellules visible 
only with the aid of the microscope, from whence, he pretends, that 
new lymphatic vessels arise, and we see, even with the naked eye, 
numerous small points, from whence a fluid runs when they are com- 
pressed. But it remains to be ascertained if these be true cells, or 
only lymphatic vessels divided. The second supposition appears 
more probable, as the larger vesicles are themselves only single local 
dilatations of the lymphatics, which continue uninterruptedly both with 
the vasa efferentia and deferentia, as Mascagni has perfectly demon- 
strated ; and secondly, a similar arrangement is observed in the venous 
system, for instance in the corpus cavernosum of .the penis and clitoris. 

The phenomena which are thought to favor the hypothesis of the 
cellular structure of the lymphatic glands, are rather opposed to it, or 
at least may be explained in another manner. It is pretended that 
these cellules become apparent, especially when the injection of a gang- 
lion is suspended after it is half filled, that one series of cells only is 
discovered when there is only a single vas afferens and deferens, 
while, when the contrary is true, several of them are observed which 
do not communicate together, since they cannot be filled except by 
pushing the injection into their proper vasa afferentia ; hence, conse- 
quently, the existence of cellules is indisputably demonstrated, espe- 
cially in the glands of the groin, by pushing the mercury through a ves- 
sel until it comes from the opposite side, provided that the vascular net- 
work which entirely covers the glands does not hinder the process. 

But these phenomena prove only, as is natural to expect, that the 
intimate structure of the glands becomes recognized more easily, when 
the external vessels are not filled with mercury. They do not demon- 
strate that the internal spaces are cellules rather than dilated vessels, 
which, of course, are filled with mercury more easily than vessels of a 
less caliber expanded on the surface of an organ. We should also na- 
turally observe the curves better, in proportion as they are fewer. 
Besides, the want of communication between the different spaces or 
curves seems to indicate that they should be considered as partial dila- 
tations of the vessels, and not as cellules. 

The external appearance of the injected lymphatic glands, with 
which also Cruikshank supported his opinion, proves nothing in his 
favor, since the projections which give these bodies the appearance 
of a grape may be curves in the vessels as well as cellules. 

Analogy drawn from the structure of animals attests only one thing, 
which is. that in some animals the ramifications of the lymphatics are 
larger than in others. 

We have reason to deny, then, the existence of cellules. We should 
even reject the opinion of those who endeavor to reconcile the two hy- 
potheses, by saying, 

First, that the glands are simple vascular twigs in some parts of the 
lymphatic system, especially in the posterior medastinum and pelvis. 

Secondly, that in other parts, particularly in the groin, they are com- 
posed both of vascular plexuses and of small cellules. 



136 GENERAL ANATOMY 

Finally, that in other regions they are formed entirely, or almost so, 
of small cellules, to which the lymphatic vessels proceed, without pre- 
viously forming any plexus. . ,. 

In fact it is not very probable that these organs, so similar in their 
other essential qualities, and which execute the same functions, should 
differ so considerably in a part of their structure in different places. 
Besides, it is probable that even where the third modification seems 
to exist, this appearance may depend on this, that the division of 
the convoluted lymphatic vessels, commences only within the 
glands.(l) 

Some anatomists, as Malpighi(2) and Mylius, have admitted, above 
the cellular capsule, a muscular membrane enveloping the substance 
of the gland, and from the internal face of which numerous filaments 
proceed, which form a reticulated tissue, in the spaces of which the vesi- 
cles are placed ; they add that the purpose of this arrangement is to 
favor the progress of the lymph. But this muscular membrane does 
not exist. 

§ 122. The lymphatics are very extensible. This is demonstrated 
by the considerable variations presented in the same part in different 
subjects, as in the lactiferous ducts, and particularly the astonishing 
size to which the thoracic canal may be increased when the passage 
of thefluid it carries is obstructed. The total disappearance of very dilated 
lymphatics, when the fluid which distends them has been evacuated by 
an incision, and the wasting of the lymphatic glands when absorption is 
completed, prove that these vessels are no less contractile. This phe- 
nomenon takes place in the lymphatics, at least in a great degree, only 
as long as life remains. We cannot then attribute it to elasticity alone. 
Besides, these vessels when touched with strong acids, not only shrink 
up, which may be attributed, at least in some cases, to the chemical 
action of these bodies on animal substances, as Bichat has done, but 
evidently contract when touched with less powerful stimulants, as the 
chloride of antimony, alcohol, hot water, and even cold air. A me- 
chanical irritation, the presence of a foreign body, the action of a cut- 
ting instrument, also cause contractions and alternate dilatation and 
closing. (3) The thoracic canal does not return to its original form af- 

(1) Lauth, jun. (Essaisur les vaiss. lymph, sect. 3, p. 29.) also denies the existence 
of cellules within the glands. Among- other proofs with which he supports his opi- 
nion, the following seem to us the most conclusive : the lymphatic glands do not ex- 
ist in the fetus : instead of them we find only simple layers, where the continuity of 
the vessels cannot be doubted ; but if this continuity be interrupted in the adult bv 
the cellules of the glands, it would follow that these vessels, continuous in the fetus 
Should cease to exist when the glands arc formed, which is not probable In birds 
we find true lymphatic glands only at the upper part of the thorax, through which 
the lymphatics of the neck pass : in all the rest of the body, the glands are replaced 
by large layers where we observe the vessels are dilated at the points of their unions 
and divisions. These dilatations are evidently what have been considered as eel 
lules in the glands, where this structure could not be as distinct as it is in birds in 
which these layers are not.'unitcd in a swlid body. p rp 

(2) Malpighi, Dc §1. con'glob.slr. annex, op.posth. p. 1.— Mylius. 

(3) Schreger, Dc irritab. vas. lymph. Leipaick, 1789, cxp. 3, 4, 7, 9 



OF THE VASCULAR SYSTEM. LYMPHATICS. 137 

ter death, as much as during life, when it has experienced a mechanical 
mjury.(l) 

We cannot deny then that the lymphatics are irritable, and we find 
no reason to attribute to them, in place of this property, a peculiar 
vitality which would render them susceptible of contracting. (2) 

On the contrary, absorption which continues after general death, the 
direct relation between the rapidity and duration of this action the se- 
lection made by the lymphatics, and their different degrees of activity, 
do not prove, as has been pretended,(3) that they are endowed with 
irritability, but only that the admission and motion of the substances 
which they contain, are phenomena dependent upon life, and not sim- 
ply on the laws of mechanics. We need not demonstrate that Bichat 
is mistaken, or at least was unfortunate in his language, in saying 
they fulfill their functions by reason of an insensible contractility. 

In the healthy state the lymphatics are not more sensible than other 
vessels, but become much more so when diseased, as in inflammation. 
§ 123. The function of the lymphatic system is to absorb, to elabo- 
rate, to a certain degree, and to carry into the venous system, the sub- 
stances presented to its radicles. The fluid it contains, then, goes from 
its branches towards its trunks and the heart. This is proved 

1st. By the phenomena already mentioned, (§ 115,) to demonstrate 
that the lymphatic system is independent of the arterial system, and 
that it arises directly from the substance of the organs and from 'their 
surfaces. 

2d. By the swelling of the lymphatics between their periphery and 
the part where they are compressed or tied, and also by their contraction 
between this point and the heart. The fluid contained by them flows 
in accordance with the same law when they are wounded. 

3d. By the direction and arrangement of their valves. (§ 116.) 
As these conditions are the same in all parts of the lymphatic sys- 
tem, the function and motion of the fluid ought also to be the same in 
all its extent. We cannot, then, admit with some ancient(4) and 
even modern(5) writers, either that the lymphatic system does not 
conduct the lymph to the heart, but carries it in an opposite direction, 
or that this motion takes place in the lymphatics of the intestinal ca- 
nal, in the lacleals, or chyliferous vessels, but does not occur in others 
in the lymphatics properly so called, where the fluid moves, on the 

(1) Ibid. exp. 2. 

(2) Ontyd, Decausis absorptionispervas. lymph., Leyden, 1795, p. 79. 

(3) Schreger, I. c. p. 53. 

(4) Bils, Diss, qua ver us h epulis circa chylum et par iter ductus chyliferi hactenus 
dicti usus demonstratur.—Ci. Haller, Depart, corp. hum. fab. i. § v. vi. 

(5) Humpage, Phys. researches into the most important parts of the animal econo- 
my, London, 1794.— Treviranus, (Untcrsuchungen uber wichtige Gegenstaende der 
Naturgese.hichte und Medicin 1803, p. 126, 128,) thinks that we ought to refuse to the 
lymphatic system the function of providing the nutritious substance designed to con- 
tinue the vital action, and to attribute it to the veins alone : 1st, because it is too nar- 
row; 2d, because nutrition takes place in aged persons when the mesenteric glands are 
obstructed ; 3d, because this function is performed in animals destitute of lymphatics. 
We shall examine these arguments farther. 

Vol. I. 18 



138 GENERAL ANATOMV. 

contrary, from the trunk to the branches, so that they immediately ac- 
complish nutrition and absorption. It is easy to refute all the argu- 
ments adduced in support of these paradoxes. 

But two problems are presented tor solution. 1. Is the function at- 
tributed to the lymphatic system constant, or, does it not fulfill also 
the opposite function which consists in the retrogradation and excretion 
of the liquids within it 1 2. Do they alone perform the function of 
absorption, or do the veins absorb ? 

I. Kratzenstein,(l) Humpage, and Darwin, (2) are the principal 
physiologists who think that the fluid contained in the lymphatics 
sometimes follows a retrograde motion. They found their opinion on 
the following facts : 

1st". The valves are no obstacle, and as they enjoy Jife, they may 
either acquire the power of acting in a contrary direction by an in- 
crease of their vitality, or be paralyzed ; in both cases the course of the 
fluids would be retrograde. 

But the increase of life can only quicken the habitual motion. Be- 
sides the valves act not only by their vitality, but also by their mechani- 
cal arrangement, so that even after death they oppose the passage of 
a fluid from the trunk into the branches, however forcibly it may be 
propelled, while they permit it to flow in a contrary direction. 

2d. The analogy of other vascular valves, which, in a morbid state, 
do not oppose the retrograde motion of the fluids and the valves of other 
organs also, as the pyloric and ileoccecal valves, overt he resistance 
of which the antiperistaltic action of the intestinal canal sometimes pre- 
vails. But these facts prove nothing : 1st, because the structure is not 
the same ; 2dly, because the valves of which we are speaking are single. 

3d. They pretend that after death the lymphatics absorb liquids in 
the opposite direction better than in the normal direction. But the ex- 
periments which have been made on this point prove, only, that the 
liquids transude sometime after death, and not that the lymphatics are 
channels which allow them to pass. 

4th. The phenomena of the urinary secretions, after the introduction 
into the stomach of substances which communicate certain qualities to 
the urine ; the changes arrive with too much rapidity for us to believe 
that the substances in question are carried to the kidneys by the circu- 
lation ; but this proves nothing, since experiments which cannot be 
doubted, prove that they are in fact carried there by the circulation. 

5th. The maladies which some have wished to explain hy this hy- 
pothesis, as diabetes, scrofula, diarrhoea, &c, cannot be conceived ac- 
cording to the theory its partisans have stated, and are explicable in 
another manner much more satisfactorily. 

II. We cannot exactly determine if the lymphatics alone absorb or 
if this function be shared also by the veins. The former hypothesis 
however, would seem more probable for the following reasons. 

1st. The obliteration of the lymphatic system prevents the escape 

(1) Theoriajlxixus diabetici more geometrico erplicati, Halle, 1746. 

(2) Zoonomia, rec. in Falleri coll. disp. praet. vol. iv. p. 51. Hanover 1795 vol i. 
p. 2. xxix. ' ' 



OF THE VASCULAR SYSTEM. LYMPHATICS. 139 

of the chyle or lymph, from the parts which inclose it. The ligature 
of the thoracic canal also causes death. 

It is true that these phenomena have been used as arguments in fa- 
vor of venous absorption,(l) but very wrongly, since where absorption 
by the veins was admitted because the lymphatics were thought to be 
obliterated, the latter were not completely destroyed ; and again, when it 
was pretended that absorption ceased after the ligature of the veins, (2) 
the lymphatics were tied at the same time, and absorption took place 
when the latter were left unobstructed. (3) 

2d. The lesion of the lymphatics produces the same phenomena, 
and wounds of their common trunk are fatal. 

3d. The substances placed in contact with an absorbing surface 
serve only to modify the action of the lymphatic system and the nature 
of the fluid it contains. 

This is proved by the fact, that at first only the lymphatic vessels 
and glands inflame and swell after infection. 

2dly. That the characteristic properties of the substances placed in 
contact with an absorbing surface have been found only in the lymph, 
and not in the blood. 

After having injected milk and colored or perfumed liquids into the 
intestinal canal of living animals, it is always observed that the liquid 
contained in the lacteals has the same color and smell ; but this is not 
the case with the blood. If the intestinal canal be filled with a colored 
liquid, and another which is easily colored, as milk, be injected into the 
arteries, it reappears colorless, when it is returned by the veins. The 
same takes place when perfumed fluids are used. Although the jntestine 
be distended with warm water, even till it bursts, the blood of the intes- 
tinal veins does not become more fluid. (4) 

Mertrud pretends to have passed liquids several times from the lac- 
teals into the azygos vein and the lumbar veins ; but he mentions 
neither the fluids used nor the means employed. (5) 

In other experiments, where water has been injected from the intes- 
tinal canal into the veins of the intestine, (6) compression has been made 
for a long time, and very probably it was torn, as is easily done, even when 
the. compression is slight. We ought also much more to suspect either 
this cause or a transudation after death in those cases where a sub- 
stance injected into the veins after death has passed into the intestinal 
canal, and in those where it has flowed back into the veins, either from 
the intestines or from other hollow organs, as the vesicular seminales.(7) 

(1) As was done by Home, for instance. See his attempt to show that fluids proceed 
directly from the stomach into the circulation without passing through the thoracic 
duct. 

(2) Lower, De Corde, vol. ii. p. 122. 

(3) Hewson, loc. cit. p. 145. 

(4) Hunter, Med. comment., p. 42. 

(5) Mertrud, Mem. ou Von se propose de demontrcr que tout le chyle n'entre pas 
dans le canal thoracique, <$*c, in Mem. present, vol. iii. p. 155-58. 

(6) Kaaw Boerhaave, De perspirat., §469-71. 

(7) Meckel, Exp. et obs. dejinibus venarum. 



1 40 G E N V. R A f. 4N4 TOM r 

One is much more authorized in this, since in the experiments of 
Hunter, the phenomena first mentioned were found as long as animal 
existence continued ; the second appeared only after death, and were 
not always constant. If water passes from the cavity of the intestinal 
canal into the veins, it transudes also in a much greater quantity on 
the surface of the intestine.(l) 

We ought here to speak of the traces of the chyle which have been 
observed in the blood of the intestinal veins. But, admitting even that 
the whitish streaks which have been taken for it were really chyle, 
they are found also in the blood of other veins ; so that they prove 
nothing. 

4th. The lymphatic system is sufficient for absorption, as the num- 
ber of its vessels is immense, and the motion of the fluid contained in 
them is very rapid. The narrowness of the thoracic canal proves 
nothing, both on account of this rapidity, and because the capacity of 
the duct varies very much, and more than one is always found. 

5th. Even the mildest substances, as water, milk, oil, air, and muci- 
lage, introduced into the venous system, endanger and destroy life. 

6th. The other arguments by which the necessity of venous absorp- 
tion is thought to be established are easily refuted. They are as follows : 

a. The veins in fact absorb in some animals which have no lym- 
phatic system. Until the time of Hewson,(2) the classes of reptiles, 
birds, and fishes, had been cited in support of this rule. Treviranus(3) 
denied the existence of lymphatics in them, even after they were 
demonstrated by Hewson. At present it can be asserted only of the 
in vertebral animals ;(4) but then we might say that absorption is- not 
performed by the vessels, and that the nutritious fluid penetrates 
every where into the substance of the organs, since there are animals 
which have not a single vessel. 

b. Absorption by the veins takes place also in certain parts of the 
bodies of animals provided with a lymphatic, system. The examples 
cited are the placenta, the penis, and the clitoris, saying that the first 
has no lymphatics, and as for the other two, the blood which is 
effused from the vessels is in fact resumed by the veins to be car- 
ried again into the circulation. But the absence of lymphatics in 
the placenta is not. perfectly demonstrated ; far from it : some observa- 
tions made lately lead us to think their existence probable. (5) Farther 

(1) Mascagni, loc. cit, 

(2) Experim. inq. London, 1774, vol. ii. ch. 4-6. 

(3) [Inters, itber icic/dige Gegents. der Natur und Medicin, Goettin»-en, 1803, p. 
127. All animals below the mammalia have no entire lymphatic system. 

(4) Magendie has resumed the observations of Hewson, and concludes from his 
own dissections that the lacteals and the thoracic canals do not exist in birds, and 
that the only traces of the lymphatic vessels are seen in the neck, where we find 
lymphatic vessels and glands, as in the mammalia, which during life are often filled 
with a diaphanous and colorless lymph. He is led to think that reptiles and fishes 
are entirely destitute of lymphatics, and that the organs described as such are 
sanguineous veins. See his Mem. sur les vaisseaux lymphaliqu.es des oiseaux in 
the Journal de Physiol, experimental, 1821, vol. i. p. 47. p T 

(5) G. Uttini, in the Mem. deW istituto nazionalc Jtaliano, vol. i. p. 11. Boio«-na 
1806, p. 209-16.— Michaelis, Obs. tirca placenta ac funiculi umbUicaiis vasa° ab- 
torbentia, Goettingen, 1790. 



OF THE VASCULAR SYSTEM. LYMPHATICS. 141 

it might be possible that, as the placenta is a temporary organ, and 
consequently less perfect in its structure, its veins had the power of 
absorption, in the same manner as they every where possess it in the 
imperfect animals. As for the penis and clitoris, the blood in them is 
never extravasated, but the pretended cells of their corpus spongiosum 
are only dilated veins ; besides, even if this were not the arrangement, 
the veins there would absorb only blood. 

c. They pretend also that it is not possible to explain satisfactorily 
the great difference between the capacity of the arteries and that of the 
veins, unless we admit that the latter receive something besides blood. 
But on one part, the veins are not so much larger during life as is stated ; 
and again, it depends, in a great part, on the obstacles to the course of 
the blood in these vessels, and the greater expansibility of the venous 
blood. 

d. Finally, the alledged difference between the venous and arterial 
blood is that the former is less coagulable, while even that of the 
vena porta does not coagulate. This assertion, however, is erroneous. 
Besides, the chyle, to the presence of which this fluidity and want of 
coagulation has been attributed, coagulates itself. (1) This difference 
is founded on the change of venous into arterial blood. 

(1) The opinion that the veins absorb may be referred even to Galen ; but it was 
rejected by Bartholin), and also by Hunter, Hewson, and Cruikshank, and after 1795 
was considered only as an historical curiosity, till 1809, when Magendie published 
his Mr moire sur les organcs de V absorption chez les mammifcres, in which he related 
his experiments made conjointly with Dupuytrcn and Delisle. (Journ. de physiol. 
experim., vol. i. p. 18. — Precis element, de physiol., vol. ii. p. 176.) The principal 
results were, 1, that if all communications between the thoracic canal and the sub- 
clavian veins were tied, the animal would perish in five or six days; 2, that the 
ligature of the thoracic canal would not prevent or even retard the death of an ani- 
mal when exposed to the influence of poison ; 3, that poison applied to a part would 
produce its effects, although this part communicated with the rest of the body only 
by its artery and vein ; 4, and finally, that perfumed or colored substances, when 
submitted to absorption, were found in a very short time in the venous blood, but not 
in the lymph of the thoracic canal. 

Magendie concluded from these results, 1, that the veins absorb ; 2, that it is 
doubtful if the lacteals absorb any thing but chyle ; 3, that it is not certain that the 
other lymphatics possess the power of absorption. Ribcs (Mem. de lasoc. med. d'e- 
mu'ation, 1317, vol. viii. p. 604 et seq.) also thought the veins absorb, having satis- 
fied himself by injections that their orifices open into the cellular tissue and cavity 
of the intestines, and having also found in the veins different substances, as fat and 
pus, while these are never seen in the arteries and lymphatics. Emmert, Mayer, 
Nasse, Jaeckel, Tiedemann, Gmelin, Seiler, Ficinus, and several others, drew the 
same conclusions, either from their own experiments or from repeating those of Ma- 
gendie. All these experiments, however, served only to prove absorption by the veins, 
and did not exclude thatof the lymphatics. To determine this point, Segalas instituted 
es of experiments in an inverse order, (Note sur V absorption intestinale, in the 
Journal dephys. exper., vol. ii. p. 11,) that is, poison was submitted to the action of 
the lacteals only ; the deleterious substance being introduced into a portion of 
intestine, having first tied the blood-vessels, taking care not to include the lacteals, 
which were seen gorged with chyle. The results were, that none of the symptoms 
of poisoning appeared when the fold of intestine communicated with the rest of the 
body only by the lacteals ; but they were seen as quickly as usual, when the blood 
passed through the vein to the rest of the body. He concluded that the veins exclu- 
sively absorb substances other than chyle which arc found in the intestinal canal. 
These experiments having been repeated several times, and always with the same 
results, many physiologists have adopted this opinion, and every day it gains new 
advocates. Fohmann (Anatomische Untersuchungen uber die Verbindun^t der 
Sacugadern mit den Venen, Heidelberg, 1821) was the first to raise doubts in re- 
gard "to these conclusions, by explaining the results of Magendie by communication* 



142 GENERAL ANATOMV 

§ 124. In regard to the duration of its action, the lymphatic system 
is one of those organs which preserve their vitality the longest. Colored 
liquids, which are injected into the chest or abdomen, or in which an 
organ is immersed, penetrate into the lymphatics forty hours after 
death.(l) 

The activity of these vessels remains longer than the irritability of 
the muscles,(2) and continues even after the animal heat has va- 
nished. (3) 

These experiments do not always succeed, (4) but we must be care- 
ful not to conclude from this that the phenomenon never takes 
place. (5) 

On the contrary, the difference observed proves that it is really 
owing to the influence of life, and that the absorption which continues 
after the death of the other organs, is not a capillary phenomenon, al- 

between the lymphatics and the veins, which he demonstrated to exist in the tissue 
of the organs and within the lymphatic glands. 

Lauth,jun., (Essai sur les vaisseaux lymphatiques, Strasburg, 1824) pursuing the 
same method, confirms the existence of the channels asserted by Fohmann; and 
then, availing himself of his own experiments, or those made by authors before him, 
which prove the absorbing power of the lymphatic vessels, drawing an argument 
too from the impenetrability of the tissues by inorganic pores, in the physiological 
state, and finally considering that the sanguineous veins are necessarily continuous 
with the arteries, and that every venous branch which arises by an open orifice is no 
longer, for this reason, a sanguineous vein, concludes, 1, that the lymphatics 
absorb ; 2, that these vessels terminate partly in the sanguineous veins, partly in the 
tissue of the organs, and in the lymphatic glands ; 3, that there seem to be substances 
which are always poured into the veins by the lymphatics, in order to be eliminated 
from the animal economy more quickly; 4, that we have no proof that the veins ab- 
sorb, and that this is even contradicted by the idea we ought to have of these vessels. 
See also on the subject Tiedemann and Gmelin, Rccherches sur la route quepren- 
nent diverges substances pour passer de I'estomac et du canal intestinal dans le sang, 
translated from the German, Paris, 1821. — Fodera, Rechcrches experimentales sur 
I'absorption et Vexhalation, Paris, 1824. — Wertrumb's Memoir on the question, Ya-t-il 
au non passage immediat des substances appliquees au corps humain, de la surface 
d'a])]>licalion dans le systeme sanguin, in the Journ. cornpl. du Diet, des sciences 
ined., vol. xvi. p. 225. — Experiences surle pouvoir absorbant desveines, by Seiler and 
Ficinus, in the same Journal, vol. xviii. p. 318, and vol. xix. p. 125. 

We observe in the Florence Anthology that Lippi has discovered several large 
lymphatic trunks which empty directly into the vena cava, in the centre of the abdo- 
men, and explains by this several of the phenomena adduced to support the opinion 
that the veins absorb. His memoir was read before the Medical Society at Florence 
on the 6th of May ; but it has not yet been published, or at least we have not 
seen it.* p_ »p. 

* These experiments have since been confirmed by M. Amussat. He injected the 
abdominal lymphatics, when the mercury passed directly from the lymphatics into 
the vena cava and the common iliac veins. This communication between the lympha- 
tic glands and the large trunks is established through the medium of certain canals 

Dr. Dubled has also injected the two inferior thirds of the thoracic duct and some 
of the neighboring lymphatics, by pushing an injection by the inferior vena cava 
But in order to this, the vein must be forcibly distended, as was verified by the fol- 
lowing experiment : the inferior vena cava having been tied below the diaphragm 
in a living animal, he found, many hours afterward, blood in the thoracic duct and 
in some other vessels of the same system.— Amer. med. journal, Mav 1830 from 
Archives generates, Nov., 1829. •" ' 

(1) Mascagni, Ichnograph.vas. lact., pp.21, 22. 

(2) Schrceger, De irrit. vas. lymph., p. 21, 22. 

(3) Ontyd, i. p. 30. 

(4) As has been frequently remarked by Mascagni. 

(5) Walther, 



OF THE VASCULAR SYSTEM IN THE ABNORMAL STATE. 143 



though the inclined position of the parts favors it.(l) Experiments 
are more successful as life is less extinct ; hence they never or seldom 
succeed in men, or animals, who have sunk under disease -(2) and are 
seen in young men better than in aged persons ;(3) when the liquid 
too is warm, sooner than when it is cold. (4) 

§ 125. These facts throw some light upon the cause of absorption ; 
it follows, then, that it is a vital phenomenon, a consequence which is 
deduced still more, 

1st. From the choice made by the lymphatics, if not always, at least 
in their normal state, between the substances presented to their ac- 
tion. 

2d. From the fact that their activity is not always the same. Con- 
nected intimately with the degree of vital energy, their activity remains 
sometimes suspended dining whole years in certain parts, as is seen 
in dropsy for instance, and reappears suddenly, often without any evr* 
dent cause, or in circumstances proper to exalt the energies of life. 



ARTICLE SECOND. 

OF THE VASCULAR SYSTEM IN THE ABNORMAL STATE. 

§ 126. In quitting the normal state of the vascular system to study 
the abnormal state, we must first seek the accidental origin of the ano- 
malies. 

They arise from inflammation supervening in the substances pro- 
duced by the coagulation of the effused fluids. As all the regular or 
irregular formations are produced by Inflammation, or an act analo- 
gous, and as this is situated in the vascular system, it appears proper 
to mention here its historical character very briefly, and attending par- 
ticularly to the form. 

Inflammation is situated in the finest ramuscules of the sanguineous 
system, in the capillaries. Blood accumulates there in greater, quantity 
than usual, and circulates sometimes with more, and sometimes with 
less rapidity than in the normal state. (5) The result of this accumu- 
lation, is to dilate the capillary vessels. (6) The part then becomes 

(1) Schrceger, loc. cit. p. 47. 

(2) Ontyd, loc. cit. p. 28, 30. 

(3) Mascagni, loc. cit. 

(4) Mascagni, p. 22. Ontyd, p. 31. 

(5) For the state of the blood vessels in inflammation, see Thompson's Lectures on 
Inflammation, Edinburgh, 1813. 

(6) This dilatation can remain even when the inflammation is discussed, whence 
the vessels are visible even on the surface of parts where before they were very mi- 
nute, as, for instance, in the pterygium. F. T. 



144 GENERAL ANATOMY - . 

redder than usual. When this state has existed some time,(l) others 
supervene, called the terminations of inflammation. But we should not 
forget that the first termination excepted, inflammation continues, al- 
though more feebly, during the consecutive .states. Sometimes inflam- 
mation disappears without leaving any traces, and then it is said to be 
resolved ; sometimes a new formation supervenes. The most simple is 
exsudation, which occurs by the effusion of the colorless portion of the 
blood, in a greater or less degree of purity, into the substance, or on the 
surface of the inflamed part. (2) As the fluid effused is more or less 
coagulable, there results from it either a kind of dropsy only, or an 
induration of the substance of the organ, or, finally, the adhesion of 
parts originally separated, but adjacent, because the effused fluid solidi- 
fies, and represents more or less the mucous or serous tissue. We 
rarely find these last two states united. Blood vessels generally deve- 
lop themselves in the effused and coagulated substance. These vessels 
are not necessarily prolongations of those which already exist, but, 
even as at the period of the first formation, the vessels appear in the 
homogeneous substance, and gradually unite with each other, as with 
those which previously existed. (3) Their structure is not so regular 
as that of the latter, and they are simple channels^) rather than real 
vessels, and are not separated by peculiar membranes from the sub- 
stance in whieh they are developed. The mucous and serous tissues, 
which are very similar, are especially disposed to adhesions of this na- 
ture, which prevent the motions of the parts to a greater or less extent. 
When this process occurs in organs which have experienced a solution 
of continuity, it is called union by adhesion, or by the first intention. 

A second kind of new formation is that of suppuration. Here the 
texture is changed more essentially, since the inflamed part becomes 
in a great measure a new secretory organ, analogous to the mucous 
membranes, and produces a peculiar fluid called pus. (5) The previous 

(1) Physicians have been led by scholastic views, dictated by empiricism, to di- 
vide inflammation into acute and chronic, terms connected with the vague idea of an 
inflammation which has continued a shorter or longer period of time. From the pre- 
tended success of stimulants in the latter state, it has been considered as opposite to 
that of inflammation ; so that acute inflammation is allied to strength, or is a sthenic 
state, and chronic inflammation with weakness, and is an asthenic state. The litter 
has been called atonic inflammation by those whose language is the most contradic- 
tory. While these scholastic speculations have been infinitely varied under the in- 
fluence of all sects, the part which inflammation takes in new or abnormal formations 
has been most generally neglected, though sometimes recognized. At this moment 
it attracts general attention. No one now, at least among us, admits asthenic in- 
flammation ; but some physiologists still deny that all new formations depend on in- 
flammation. We shall return to this subject in a note to Section XII. F. T. 

(2) Hunter on the Blood, &c. 

(3) See, on this subject, an important note of Th. Dowler, Sur les produits del' in- 
flammation aigile : in the Journ. comptem. du Diet, des sciences med vol xviii n 

188. " ' K ' 

(4) Bordeu, Recherches sur le tissu muqueux, Paris, 1767, p. 28. See on this sub- 
ject, the important note of Home, on the changes which take place in the blood in 
coagulating, in the Phil. Trans. 1818, p. 172-185. 

(5) Brugnians, De puogenis, Groningen, 1785.— Home, On the properties of pus, 
London, 1788. — Pearson, Observations and experiments on pus, in the Phil. Trans'. 



OF THE VASCULAR SYSTEM IN THE ABNORMAL STATE. 145 

formation of this organ is, however, not indispensable to produce pus ; 
thus it is not observed in the mucous membranes. In general, in order 
that suppuration should take place, the inflammation must have at- 
tained a certain degree of intensity, and have lasted a certain length of 
time. But these conditions are not rigorous. 

The fourth iermination of inflammation is by sphacelus of the part 
which is preceded by gangrene. The first of these states is called 
moist, the second dry gangrene. The bright red color changes to a 
deep red. and soon becomes black ; the mortified part then undergoes 
changes, which every organized body experiences after its death.(l) 

When this state occasions only the death of the inflamed part, the 
gangrene is arrested. There forms then on the limit of the dead and 
living part a reddish fissure, a furrow along which the living part ap- 
pears of a bright red. 

This furrow is produced by absorption, which becoming more ac- 
tive, endeavors to separate the dead from the living parts. 

The means of restoration are more complex where suppuration and 
mortification occur than where resolution and adhesion only take place. 
There are developed on the surfaces which secrete pus, small reddish 
elevations, formed of mucous tissue, and of minute vessels ; these are 
called granulations. These gradually unite, contract, and finally form 
a cicatrix, which is smaller in all its dimensions than the diseased part, 
and which has more or less perfectly the structure of the organ it 
replaces. (2) 

§ 127. Although in parts newly formed new vessels also are deve- 
loped, of which some arise independently of those already existing, 
while others are simple prolongations of the latter, (§ 126), the old 
vessels do not possess the power of being entirely regenerated. When a 
vessel is destroyed by a ligature, or in any other manner, a new vessel 
is never formed in its place. Even when a wound made in a vessel 
heals by cicatrization, and the canal is not obliterated, this vessel al- 
ways differs in hardness and indefinite texture from those which have 
never been injured, although Maunoir advances the contrary. What 
this anatomist considered as the commencement of regeneration, was 
merely an imperfect closure of the artery. (3) 

§ 128. The four portions of which the vascular system is composed, 
viz. the heart, arteries, veins, and lymphatics, present a great many 
anomalies in their external and in their internal form. Of these many 
are common to all, while others belong more particularly, or even strictly, 
to one of them ; but those which are formed indefinitely in the four 
portions of the system, are more or less modified, by differences in the 
normal structure of each one. 

(1) For the state of the blood vessels in gangrene, see Thompson's Lectures on In- 
flammation, p. 352. 

(2) Moore, On the -process of nature in the healing of wounds, London, 1789. — 
Home, On the change of pus into granulations, in the Phil. Trans. 1819, p. l-ll. 

(3) Maunoir, Mem. sur I'anevrysme, Geneva, 1802, p. 108. 

Vol. I. 19 



146 GENERAL ANATOMY. 

We may establish the following classification. The aberrations of 
the vascular system are divided into anomalies : 1st, of their external 
form ; 2d, of their internal form, or texture, and of their chemical com- 
position. 

The former relate, 1st, to their situation; 2d, to their mass and 
volume ; 3d, to their figure ; and 4th, to the continuity of the system. 
All these anomalies may be congenital, or produced accidentally by 
influences which act contrary to rule. Not being able to enter 
into' a minute description of all the peculiarities which, to be well un- 
derstood, should be referred to special anatomy, we shall confine our- 
selves to the following remarks. 

§ 129. I. The anomalies of situation are marked in the vessels princi- 
pally by an unusual character in their origin and course ; in the heart, 
by changes in its directional ) 

§ 130. II. Anomalies in mass and volume, consist in an excess or 
diminution in the vessels from the normal state. The mass and volume 
are not necessarily increased or diminished both at once ; the anoma- 
lies in these respects are often at the same time opposite. Increase in 
mass and volume is more common than diminution and contraction. 

Enlargement is not usually attended with change of texture in the 
heart, veins, and lymphatics. It is«often attended in the heart with an 
increase of substance, while, generally, there is only a dilatation in the 
veins and absorbents. As to the arteries, when they are dilated, we 
observe not only an alteration of texture, but a partial rupture. 

The history of the special alterations presented by the heart in 
this respect, also belong to special anatomy ; but the history of those 
of the other portions of the vascular system may be given here. 

Abnormal dilatation in the arteries is called aneurism (aneurisma.)(2) 
Nevertheless, by this term we mean several states of thearteries which 
are essentially different, viz. 

1st. The total or partial dilatation of their circumference. 
2d. The total or partial destruction of their continuity. 
These two states are still distinguished from each other by the term 
true aneurism applied to the first, and of false or mixed aneurism to the 
second. 

By true aneurism, (aneurisma verum), we usually understand simply 
a dilatation of the circumference of the arteries. Such a 'state is pos- 
sible, and sometimes even occurs ; but it is extremely rare, and seldom 
exists in the cases usually supposed. Although this does not take place in 
all circumstances, there is more frequently a slight dilatation, accom- 
panied by a morbid alteration of the inner membrane of the artery, such 
as inflammation, formation of cartilage, fragility of this tunic, and 
afterwards, when the dilatation has progressed, the internal and fibrous 
membranes are ruptured, blood is effused into 1 its cellular membrane 
through the fissure, which is always more or less perceptible. 

(1) See our Memoir on the primitive deformities of the heart and large vessels in 
Rett's Archivfitr die Physiologie, vol. vi. p. 3. 

(2) The principal writer on this subject is Lauth, Collcctioscriptorumlatinorum dc 
aneunsmatibus, Strasburg, 1785.— Scarpa, On aneurism. 



OF THE VASCULAR SYSTEM IN THE ABNORMAL STATE. 147 

The cellular membrnne already, before this, intimately adhered to 
the inner tunic, either from its diseased state or from compression ; so 
that, whether the rupture be sudden or gradual, no effusion of blood 
could occur which, by its unlimited duration, should cause death. 
Hence, why the artery is not uniformly distended in large aneurisms ; 
we observe on the artery only the sac produced by the cellular tunic', 
which is usually united to it by a narrow neck. This sack adheres to 
the parts adjacent, but the pressure of the blood gradually or suddenly 
destroys it. When the part destroyed corresponds to a hard part, espe- 
cially to a bone, and the opening every where adheres to this part, no 
fluid escapes from it ; but when its adhesion to another organ, which 
is not itself protected, is torn, the blood rushes from the opening, runs 
slowly or rapidly into a cavity of the body, or into another organ, 
even to the surface of the body, and death sooner or later occurs. Such 
at least is the usual result of true aneurism. When the tumor is left 
to itself, an inflammation, accidentally developed, rarely obliterates the 
vessel in its diseased portion, and the circulation is very seldom re-esta- 
blished by the dilatation of the collateral arteries. 

These remarks demonstrate that most of the aneurisms regarded as 
true, are in fact mixt ; since there is, at the same time, a rupture' of 
the internal, and a distention of the external, tunic. Simple dilata- 
tion of the arteries rarely occurs, except in organs which enlarge 
much : since, then, the artery participates in the increase of nutri- 
tion ; still this does not always happen even in this case. 

The arterial system is sometimes more or less disposed to this mor- 
bid alteration, in a greater or less portion of its extent. This is termed 
an aneurismatic diathesis [diathesis aneurismatic a) ; in it we find 
several aneurisms in the different parts of the same body, and in the dif- 
ferent arteries of the same part. Such a predisposition is not however 
necessary ; and whether there be or be not fragililty of the arterial tu- 
nics, external mechanichal influences can produce this effect, although 
these causes are generally confined to alterations of the tissue in the ar- 
teries of those parts upon which they act. 

The false aneurism (aneurisma spurium) does not deserve the name 
of aneurism, since it does not consist of a dilatation, but merely a solu- 
tion of continuity in the artery. It is produced generally by an exter- 
nal injury, frequently by bleeding when the artery is opened instead of 
the vein. Hence it is found more particularly at the lower end of the 
brachial artery ; accordingly then, from different causes, as the blood 
is diffused through the whole limb between the muscles and beneath 
the skin, or pervades only a small space, the aneurism is termed dif- 
fused, (aneurisma dlffusum,) or circumscribed, (aneurisma circumscrip- 
tum.) 

The mixt aneurism (aneurisma mixtum) of authors is where some of the 
membranes of the artery are ruptured, and others are simply distended. 
They admit that the external membranes may be ruptured, and the 
inner membranes distended, or the latter may be ruptured and the for- 
mer dilated. 



148 GENERAL ANATOMT. 

The latter, as we have stated, generally occurs in a true aneurism. 
The first is necessarily very rare, since the removal not only of the 
external coat, but also that of the middle membrane, occasions no dila- 
tation in the vessel, even when the adjacent parts of the artery do not 
protect it.(l) 

Besides these abnormal states which relate to the arteries only, the 
lesion of an artery may be attended with that of the veins. If then the 
wounds are so placed that the two vessels open into each other, there 
results a varicose aneurism (aneurisma varicosum, varix aneurismali- 
cus), called also, but improperly, a mixt aneurism.{2) 

This accident is rare and purely fortuitous in the aneurisms deter- 
mined by aninternal cause, which are usually considered as true aneurisms . 
It may be that the sac then opens into an adjacent vein, or into a ves- 
sel carrying black blood, (3) to whichit adhered before, and the parietesof 
which it finally destroyed at the point of contact. But the accident is 
more common and necessarily supervenes where an external lesion pro- 
duces an ordinaryfalse aneurism, when ihe vein has been pierced through 
and through with the corresponding wall of the artery which accompa- 
nies it. The blood runs, then, from the artery into the vein and surround- 
ing cellular tissue ; but the nearness of the two vessels, the ease with 
which the blood passes from the artery into the vein, and the effect of 
compression, cause the two corresponding openings to close, as also the 
external wound of the vein, and an abnormal communication between 
the two vessels only remains. 

The dilatation of the veins(4) (varix), and that of the lymphatics,(5) 
(cirsus) are seldom attended with a degeneration of the membranes. 
They depend upon a simple dilatation more frequently than the aneu- 
rism, because the veins and lymphatics are much more extensible than 
the arteries. They mostly arise from mechanical obstacles which 
oppose the free course of the fluids. Nevertheless, ruptures some 
times occur when the distension progresses too far. 

The partial dilatations of the lymphatics, which occur between two 
pairs of valves, and which are attended with the obliteration of the ves- 
sels, can give place also to the formation of a kind of hydatids, which are 
much more rarely developed in the veins from this cause. 

(1) Hunter in the Transact, of a soc. for the improvement of med. and sure, 
knowledge, vol. i. p. 144. 

(2) Hunter, History of an aneurism, in Med. obs. and inq. vol. i. No. 26. p. 340.— 

Farther observat. uponapartic. species of aneurism, ibid. vol. ii. No. 36. Cleghorn 

Case of an aneurismal varix, ibid. vol. iii. No. 13.— White, On the varicose aneurism 
ibid. vol. iv. No. 34.— Armig-er, On varicose aneurism, ibid. No. 35.— Brambilla Von 
der blutader igten Schlagadergeschwulst, in Abh. d. Joseph Akad. vol. i p 92 — Lar- 
rey, in the Bullet, de lafac. de med. 1812. No. 1-3. ' 

(3) Wells, A case of aneurism of the aorta communicating with thepulmonary arte- 
ry, in the Transact, of a soc. for the improvement of med. and sure knowledge 
vol. iil. No. 7. o e > 

(4) F. A. B. Puchelt, Das Venensystem in seinen krankhaften Verhdltnissendar- 
gestellt, Leipsick, 1818. 

(5) Soemmerring, De morbis vasorum absorbentium corporis humani, Frankfort, 



OF THE VASCULAR SYSTEM IN THE ABNORMAL STATE. 149 

Abnormal dilatation of the vessels affects, usually, but one system. 
Still it is not rare that it extends to all the three together. The capil- 
laries are then always diseased. The disease appears as a red pul- 
sating tumor which bleeds often, and is composed of a complicated tissue 
of vessels ; it is frequently found in the subcutaneous cellular tissue, 
and called aneurism by anastomosis, angieciasia, or accidental cavernous, 
or erectile tissue. 

§ 131. The opposite state, the abnormal smallness and narrowness 
of the vascular system, is much less common than the preceding. It 
is rarely general. For the most part it affects only one series of ves- 
sels ; and the abnormal contraction of one, determines an unnatural 
enlargement of the other. 

This state may be only a simple defect, of formation, or depend on a 
morbid alteration of texture. To this is referred the contraction of the 
canal by an effusion of fibrous matter supervening to inflammation of 
the vessels. But in most cases this effusion not merely contracts the 
vessels, but it entirely obliterates them. 

The vessels always diminish gradually, contract, and are obliterated 
without previous inflammation, when the blood no longer flows within 
them, whether this state be connected with the regular develop- 
ment of the organism, as for instance in the obliteration of the um- 
bilical arteries and veins, or depends on some accidental cause. 

§ 132. III. The peculiar conditions of the abnormal form of the vascu- 
lar system, cannot be examined here, any more than those of its abnor- 
mal situation, and for the same reasons. Besides, the anomalies of 
configuration and of situation usually accompany each other, at least 
in the primitive deviations of formation. We shall only observe here, 
that most of the anomalies of configuration are congenital, and may 
all be referred to two classes : the first comprises those, the results of 
which are attended only with an irregularity in the motion of the blood, 
while the second embraces those which, consisting in an unusual com- 
munication between the systems of red and black blood, derange the 
formation of blood, and cause the disease called the blue disease, {mor- 
bus cozrulceus,) or cyanopathia, from its most prominent symptom, the 
abnormal discoloration of the skin. 

§133. IV. The investigation of the changes which supervene after 
the wounds of the vessels, especially of the arteries, are healed, is very 
important. We must examine here, 1st, the total and partial solutions 
of continuity ; 2dly, wounds from stabs and incisions ; 3dly, the lon- 
gitudinal and transverse wounds ; finally, the phenomena produced by 
ligatures of the vessels.(l) 

(1) Petit, Mem. sur la maniere d'arreter les hemorrhagies, in Mem. de Vac. 
des sc. de Paris, 1731-1732. — Morand, Sur les changemens qui arrivcnt aux artiret 
couples, in Mem. de Paris, 1736, p. 440-450. — Ponleau, Ven den mitteln vel che 
die natur anivendct Blulungen zu stillen, &c, Dresden, 1764.— Jones, On the pro- 
cess employed by nature in suppressing the hemorrhage from, divided and punctured 
arteries, London, 1815.— Travers, Observations on the ligature of arteries, in the 
Medico- Chirurg. transact., London, 1813, vol. iv., p. 434-465. 



150 GENERAt ANATOMY. 

The ordinary mode of healing in wounds of the arteries is the obli- 
teration of the vessel by inflammation. This occurs even when t licit: 
is no solution of continuity, when a ligature is merely passed around 
the artery, and is removed after being drawn tightly. The effect of 
this constriction is always to cut the two internal tunics without in- 
juring the external; consequently it produces a wound in the first 
two, and changes them into a secretory surface, which immediately 
adheres. In some experiments made expressly, adhesion took place 
immediately, one hour after the application of the ligature, for the 
pulses were not perceptible in the side operated upon, even after the 
ligature was removed.(l) When we merely tie the ligature and im- 
mediately remove it, the circulation is, at first, uninterrupted ; some- 
times, but not always, obliteration takes* place immediately,(2). which 
proves that it does not result from the coagulation of the blood, but from 
inflammation and from exudation. The artery is obliterated, not only 
at the part on which the ligature or compression acts directly, but its 
cavity is almost always effaced from this point to the first branch it 
gives off. In this part it becomes a fine cord, and finally entirely disap- 
pears, while the collateral branches dilate in a greater or less 
degree (§94). 

This occurs necessarily when the whole extent of the vessel has been 
divided crosswise. But the pricks, the cuts, which implicate but 
a small portion of the" arteries, can heal without the obliteration of 
the vessel, and even without the diminution of its cavity, or at least 
without any considerable contraclion.(3) It is then possible to heal 
certain wounds of the arteries by cicatrization without obliteration, 
although(4) the latter frequently results from the method employed to 
form a cicatrix. (5) 

The following occurs in all wounds of the vessels. Elood escapes 
from the wounded vessel and coagulates. If the lesion be inconside- 
rable, and the circulation uninterrupted, the effusion takes place only 
on the external surface of the artery ; but the coagulated portion pro- 
jects a little internally, and soon adheres on one side with the edges of 
the wound, and on the other with the portions of the external surface 
of the vessel which immediately surround it. If the vessel be entirely 
divided, it contracts very much, both lengthwise and across, after the 
e*ff usion of blood. The blood which remains around it, and that which 
rests in its cavity, coagulates, whence results a transitory obliteration ; 
but afterwards the internal membrane of the artery inflames all the 
internal surface of the vessel adheres, and its cavity is completely 
effaced. 

§ 134. The alterations of tissue in the vascular system are 

1st. Inflammation and its consequences, which act on all the por- 
tions of this system, and which very often, by the exudation with which 

(1) Travcrs, loc. cit. p. 463. 

(2) Travers, loc. cit. p. 442. 

(3) Jones, loc. cit. p. 151. 

(4) Lambert, A new method of treating aneurism, in the London mcd. obs. and 
inquiries, vol. u. p. 3b0. 

(5) Asman, De ancurismatc, Groningen, 1773. 



OF THE VASCULAR SYSTEM IN THE ABNORMAL STATE. 151 

they are followed, determine the obliteration, even of the larger trunks, 
especially in the venous(l) and the lymphatic system, for they attack 
principally their internal membranes. Inflammation sometimes causes, 
particularly in the veins, a chain of abscesses, which progress along 
thair course,(2) gradually open externally , and by cicatrizing, obliterate 
the vessel. 

2d. Ossification of the vascular system is not rare. It depends un- 
doubtedly, like other new formations, particularly that of the osseous 
tissue, on an increase of blood. But the state which precedes it 
hardly deserves the name of inflammation. 

The principal phenomena in the ossification of the vascular system 
are : 

a. Ossification always takes place in the internal membrane. 

6. The newly formed osseous substance appears as scales of dif- 
ferent breadths, which cover more or less of the vessel. 

c. Very commonly the internal membrane, in this part, is either 
totally or partially destroyed. 

d. These ossifications develop themselves almost exclusively in the 
, system of red blood. They are very common in the arteries, especially 

the descending aorta below the diaphragm, in the arteries of the lower 
extremities, and in the left ventricle of the heart. The venous portion 
of the system of red blood, and all the system of black blood, on the 
contrary, rarely afford instances. They are not rare in the lymphatic 
glands, even in young subjects. In fact, these small bodies often seem 
to be entirely ossified ; but when attentively examined, we find a greater 
or less portion, which has undergone no alteration. 

e. They are more common in the male than in the female. 

/ Ordinarily they supervene only at an advanced age (§ 86) . Still we 
ought to consider them as a morbid state ; for, although they are often 
met with in Europeans, there are aged persons who offer no traces of 
them, and they are rare in the West Indies. (3) Besides they are 
sometimes developed in young men, both in the pulmonary artery, and 
in the system of red blood. 

Fragility in the arteries(4) is somewhat allied to ossification ; this 
sometimes exists alone, but almost always accompanies the anoma- 
lous development of the osseous tissue. 

Of all portions of the vascular system, the lymphatic glands are 
almost the only parts liable to be converted into formations entirely 

(1) Bouillaud, De V obliteration des veincs, et de son influence sur la formation des 
hydropisics partielles; in the Archives generates de medecine, June, 1823, p. 188., 
May, 1824, p. 94. — Id., Observations sur I'etat des veines dans les infiltrations des 
membres; in the Journal dephysiol. experiment, vol. iii. p. 89. 

(2) J. Hunter, Observations on the inflammation of the inner coats of veins; in 
the Trans, of a soc. for impr. of med. and surg. knowl., London, 1793, vol. i. no. 2. 
— Schmuck, Diss, de vasorum sanguiferorum inflammatione, Heidelberg, 1793. — 
Sasse, Diss, de vasorum sanguiferorum inflammatione, Halle, 1797. — tipang-enberfr, 
Sur V inflammation des arteres et scs terminaisons ; in Horn. Archivfur med. Er~ 

fahrung, vol. v. p. 2. no. 1. 

(3) Stevens, in Medico-chirurg. transactions, vol. v. p. 434. 

(4) Malacame, Osserc. in chirurg. vol. ii., Turin, 1784, art. xii. p. 160. 



152 GENERAL ANATOMY. 

anomalous. These formations are sometimes primitive, as in scrofu- 
lous patients, where the lymphatic glands swell, and finally are par- 
tially or totally changed into a whitish albuminous substance ; this is 
rather hard at first, but afterwards alters to a thick, grumous pus. 
They may grow by infection when a contagious principle, absoibecLin 
a part before diseased, arrives at the lymphatic glands, which react 
rapidly upon it, as it is their function to assimilate foreign substances. 
Hence inflammation, tumefaction, and suppuration of these organs, 
and their changes into morbid tissues analogous to those already pre- 
viously developed in other parts, with which they communicate by 
means of lymphatic vessels, as is observed in different kinds of ulcers, 
in cancers, &c. 



SECTION III. 

OF THE NERVOUS SYSTEM. 
ARTICLE FIRST. 

OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 

§ 135. The nervous system (systema nervosum) (1) of man, and of 
most animals, namely, of all those which have a vertebral column, 
comprises two portions : the one, more or less globular, terminates 
in a prolongation similar to a tail ; it is inclosed in the cavity of the skull 
and spine. The other is composed of elongated fine rays, which ramify, 
and which, being attached to the former by their central extremities, are 
expanded through the whole body among the other organs, which are 
partly formed by their other extremity, or periphery. The first portion, 
called the central or internal, is composed of the brain, (encephalum),(2) 

(1) Willis, Cerebri anatome nervorumque descriptio et usus, Geneva, 1676. — 
Vieussens, Neurographia universalis, Lyons, 1684. — J. C. Mayer, Abhandlung vow. 
Gehirn, Ruckenmarck und dem Ursprungc dcr Nerven, Berlin, 1779. — G. Pro- 
chaska, Destructura nervorum tractactus anatomicus, Vienna, 1779. — Monro, Obser- 
vations on the structure and the functions of the nervous system, Edinburgh, 1783. — 
Vicqd'Azyr, Recherches sur la stucture du cerveau ; in the Mcmoires del' academic 
des sciences de Paris, 1781, 1783. — Pfeffinger, Diss, de structurd nervorum, Stras- 
burg, 1782, 1783. — Metzger, Animadversiones anat. physiol. indoctrinam nervorum, 
Koningsberg, 1783. — Gall et Spurzheim, Recherches sur le systeme nerveux, Paris, 
1819. — Carus, Anatomic und Physiologic des Nervensystens, Leipsic, 1814— Wede- 
meyer, Physiologischc Untersuchungen uber das Nevrensystem und die Respira- 
tion, Hanover, 1817. — Nasse, Veber das verhaltniss des Gehirns und Ruckenmarks 
zur Belebung des ubrigen Korpers. Halle, 1818.— Georget, De la physiologic du 
systeme nerveux, specialement du cerveau ; recherches sur Iss maladies nerveuses, 
etc., Paris, 1821. 

(2) Malpighi, De cerebro; in the Epist. anat. de cerebri cortice ; ibid.— Vicq 
d'Azyr, Traite d'anat. et de phys., Paris, 1786.— J. and C. Wenzel, De pcnitvori struc- 
turd cerebri hominis et brutorum, Tubing-en. 1812.— Reil, Fragmcnte uber die Bil- 
dung des Gehirns ; in the Archiv fur die Physwlogie, vol. viii. ix. xi. — Rolando, 
Saggio sulla vera struttura del cervello dell' uomo, Sassari, 1809.— Rosenthal, Ein 
Bcytrag zur Encephalotomie, Weimar, 1815.— Gordon, Observations on the struc- 
ture of the brain, Edinburgh, 1817.— Burdach, Vom Bau und Lebcn des Gehirns, 
Leipsic, 1819-1822. — Tiedemann, Anatomic du cerveau, transl. by Jourdan, Pari3, 
1823.— Serres, Anatomic compareedu cerveau, Paris, 1824. 



tV THE NERVOUS SYSTEM IN THE NORMAL STATE. 153 

and of the spinal marrow (medulla spinali Si )(l) ; the other, the exter- 
nal or peripheric, is the nerves. (2) 

Those nerves which arise from the brain are called the cerebral 
nerves, (nervi cerebrales,) and those coming from the spinal marrow 
are called the spina/ nerves (nervi spinales). The whole number is 
forty-two pairs, twelve of which are cerebral, and the other thirty 
spinal; strictly speaking, however, there are only eleven pairs of cere- 
bral and thirty-one of spinal nerves. 

§ 136. It is in the nervous system especially that we discern that 
the body is composed of two lateral corresponding portions. In fact, all 
Its parts are double, or when simple are placed near the median line, 
along which the two halves which constitute them unite, and blend in 
one mass. This arrangement is observed equally in the central por- 
tion, and in the periphery. At the same time the two lateral parts 
correspond exactly in all the nervous system, so that they vary less 
in situation, form, and volume, than other organs, and it is often im- 
possible to perceive the least difference between them. This system 
is then symmetrical in the strictest sense of the word. The symmetry 
appears especially in the brain and spinal marrow, and the nerves 
which are immediately attached to these two organs. It is less 
marked in the great sympathetic nerve, a part of the system almost 
isolated from the rest. This difference deserves to be more attended 
to, because the symmetry of the organs corresponds exactly to that of 
the portion of the nervous system with which they are connected. All 
parts of the brain, the spinal marrow, and their nerves are not how- 
ever equally symmetrical. The external is less so than the internal 
portion. Hence why the surface of the brain and the arrangement 
of the extreme ramifications of the nerves on the right and left sides 
differ more than the deep portions of the encephalon, and the origins 
of the nerves on both sides. 

§ 137. The structure of the nervous system is also very constant 
It is indisputably the system of organs in which we find the fewest 
anomalies. In this respect however the same difference exists between 
its parts as in the preceding ; for the great sympathetic nerve presents 
numerous and considerable variations in every respect, while the in- 
ternal parts, especially the origins of the nerves, are very constant 
We have no instance of a nerve arising from any other than its usual 
point ; unlike the vascular system, in which anomalies, even of the 
largest trunks, are very common. 

J^ n H l& f^U Medull ^ S i in( il is 2 na t-> Amsterdam, 1666.-J. J. Huber, De medulla 
«n 17Rfl r% e \ m J\~n- C - f^her Descriptio medulla: spinalis, Erlan- 
f/t?,V// 77," y K( r nffel < De medulla spmah diss., Halle, 1810.— Racchetti. Bella 
struttura, delle funzwne e delle malattie della midolla spinale. Milan, 1816.— Olli- 
Xnrk iT l sur ^ Va 1 natomie et les vices de conformation de la motile epiniere, Paris 
Zi,\Z .' ■ l la V }? elle tP ini z re et de se $ maladies, Paria, 1823.-Rolar.do, Ri- 
cercfteanatomtche sulla struttura del midollo spinale, Turin, 1824. 
1 7A7 A ™? man . n > Versuch uber die Regeneration an lebenden Thieren, Gottingen. 
Halle 1797 P " P " 127_308,— Rei1 ' Exercitationes anatomicce de slrudurd nervorum, 
Vol. I. 20 



154 GENERAL ANATOMY. 

§ 138. Considered either in regard to symmetry or structure, the 
nervous system of man is less regular than that of other animals, 
even those which are nearest to him. This remark has already been 
made by Vicq d'Azyr ;(1) and the observations of Wenzel(2) prove 
its justice. In fact the halves of the nervous system correspond more 
perfectly in the mammalia, and the deviations from the normal state in 
these animals are rarer than in man. 

§ 139. The nervous system is composed principally of semi-coagu- 
lated albumen. We find, besides, two kinds of fatty matter, a peculiar 
reddish-brown gelatinous substance, osmazome, phosphorus, sulphur, 
hydrochlorate of soda, and several phosphates.(3) The analysis of 
the brain of man gives the following results : 

Water 80.00 

Whitish fatty substance ----- 4.53 

Reddish fatty substance, called cerebrine 0.70 

Albumen 7.00 

Osmazome 1.12 

Phosphorus - - - - 1.50 

Salts and sulphur - - - 5.15 

Total, 100.00 

The spinal marrow and its upper part, the medulla oblongata, have 
the same chemical composition ; but they differ from the brain in con- 
taining more fatty matter, and more albumen, osmazome, and water. 

In the nerves on the contrary, we find less fatty substance and more 
albumen than in the brain. (4) 

§ 140. This system is mostly formed of a white and soft substance 
called the medullary substance, (substantia medullaris.) This sub- 
stance alone probably constitutes the nerves. In the central part of 
the system we find an abundance of another substance called the 
gray or cineritious substance, (substantia cinerea,) from its color, and 
the cortical substance (substantia corticalis,) because it forms the 
external layer of the brain, where it envelopes the medullary sub- 
stance. Finally, the brain contains more or less of a third substance, 
the yellow substance, (substantia flava,) and, besides these two, in some 
parts, even a fourth, the black substance, (substantia nigra;) but 
properly speaking, these are simple modifications of one and the 
same substance. 

§ 141. Besides their difference in color, these substances vary from 
one another in many respects : 

(1) Mem. de fAcad. des sc, 1783, p. 470. 

(2) Wenzel, Prodr. et De penit. cer. struct, chap. iii. 

(3) Pourcroy, , in the Ann. de chimie, vol. xvi. p. 282-322.— Vauquelin, Analyse de 
la mahere cerebrate de I'homme et des animaux, in the Ann? du Mus. d'hist. 
naturelle, vol. xvm. p. 212-239. 

(4) Home, Observations on the brain and nerves, proving that their component 
materials exist in the blood, in the Philosoph. Transact. 1821, p. 25.-Chevrcul has 
detected cerebrine in the blood.— F. T V 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 155 

1st. In their proportional quantity . The medullary substance exceeds 
the cortical substance, although in certain parts of the brain the latter 
is more abundant. 

2d. In structure. Their final elements of form are in fact the same ; 
but we remark in the medullary substance that they more evidently 
combine to produce secondary formations, as we shall show hereafter. 

3d. In their physical qualities. The gray substance is softer and more 
fluid than the medullary substance ; it also diminishes more in drying. 

4th. The gray substance receives more blood vessels than the medul- 
lary substance ; hence it has been considered as entirely vascular ; 
but this is not probable, since even the most successful injections do 
not change it into a tissue of vessels. 

5th. The gray substance differs perhaps a little from the medullary 
substance in chemical composition. It is said not to contain phos- 
phorus. (?) (1) 

This substance is not similar in all parts. Thus it is paler in the 
tubercula quadrigemina than in the thalami optici ; paler too in the 
latter and on the surface of the brain than in the corpora striata. The 
yellow substance is less abundant than the gray, and the band it forms 
between the latter and the medullary substance, is narrower than the 
gray stratum. Still the gray substance forms considerable masses in 
different parts ; for instance, in the centre of the cerebellum, in the cor- 
pus fimbriatum, and the eminentia olivaria. It is there also firmer 
than the medullary substance. 

The black substance is found only in a few parts. There is also in 
some parts a bluish substance. (2) 

§ 142. The structure of the nervous system is every where the 
same, at least in its essential characters. Its remote elements of form are 
globules, united by a semi-fluid substance. (3) These globules are found 
both in the medullary and cortical portions, in the brain, spinal mar- 
row, and in the nerves. Opinions vary in regard to their form and 
size, and to the degree of consistence of the substance which unites 
them. 

§ 143. According to Delia Torre, these globules differ in volume 
and transparency in all parts of the nervous system ; the largest 
being found in the cerebrum so called, the next in size are those of the 
cerebellum, while those of the medulla oblongata are still smaller, 
although larger than those of the medulla spinalis ; the smallest and 
most opaque are found in the nerves ; even in these they vary in size, 
diminishing continually from the origin of the nerves to their termina- 
tions. The globules .of the cortical, are always larger than those of 
the medullary, substance. 



(1) John, Chemische Tabellen des Thierreichs, Berlin, 1814, p. 74. 

(2) Wcnzel, loc. cit. chap. 16. 

(3) Delia Torre, Nuope osservazioni microscopiche, Naples, 1776, p. 16-21. — Pro- 
chaska, De structura nervorum,, Vienna, 1779, sect. ii. c. 10. — Wenzel, loc. cit. 
chap. iv. — A. Barha, Osservazioni microscopiche sul cervello e sulle parti adjacenti 
Naples, 1807.— Home and Bauer, in the Phil, trans., 1821. 



156 GENERAL ANATOMY 

Prochaska and Barba on the contrary think that the globules are of 
the same size in every part of the nervous system ; and that the dif- 
ference remarked by some depends on the difficulty of separating from 
each other. 

Prochaska estimates their size at one eighth of those of the 
blood ;(1) but he thinks they are not all similar in this respect, even 
in one and the same part. 

It has not yet been ascertained whether they differ regularly at 
different periods of life, as has been observed in certain animals. (2) 

§ 144. They are not perfectly round. Whether they are hollow or 
solid has not yet been determined ; because, from their smallness, and 
from optical deception, this part of their history is ascertained with 
difficulty. 

§ 145. According to Prochaska, these globules are united by a deli- 
cate cellular tissue. Delia Torre thinks, however, that it is by a 
transparent viscous fluid, more tenacious in the medullary than in the 
cortical substance. In the different parts of the nervous system the 
viscidity of that which belongs to the medullary substance increases in 
the same ratio as the size of the globules decreases. 

Barba says, however, that this difference is only imaginary, and 
depends on the length of time which elapses between death and. the 
moment of observation. 

§ 146. These two elements of form unite in all parts of the nervous 
system, giving rise to fibres, most of which are longitudinal. 

§ 147. In no system is this fibrous structure more apparent than in 
the nerves. Almost all the nerves are formed of a greater or less 
number of fasciculi, visible to the naked eye, these are composed of 
smaller cords,(funes) and these again of minute filaments {fila.) The 
fasciculi, cords, and filaments ramify and anastomose extensively ; and 
we cannot find a single fasciculus which extends any distance in a 
straight line. At the ends of the nerves these ramifications and com- 
munications are fewer than in their course. The size of the filaments 
and cords formed by them differs not only in different nerves, but even 
in the same nerve. Their diameters vary from one tenth of a line to 
several lines. They are thicker in the body of a nerve than at its 
extremities, where they separate and become smaller. All the nerv- 
ous fasciculi, whether formed of large or small collections of fibres, 
follow the longitudinal direction of the nerve. 

§ 148. The medulla of the nerve is not loose. . Each filament, even 
the smallest, has a special sheath which closely envelopes it, and 
which is formed like the filament. Hence when the medullary sub- 
stance is removed by an alkaline solution, the tunnels represent the 
form of the entire nerve, and the medullary substance exhibits the 

(1) Loc. cit. p. 72. 

(2) Carus thinks that the globules are arranged in masses in the central Dortions 
and m regular lines in the nerves. Milne Edwards determined that the P nervo^s 
substance of the encephalon, of the spinal marrow, and of the nerves in th four 
classes i of vertebral animals, is formed of globules of ' of a mEetf^nited in 
.a series so as to form primitive fibres which are considerably long.— F. T. 



OP THE NERVOUS SYSTEM IN THE NORMAL STATE. 157 

same appearance when its tunic is removed by immersion in an 
acid.(l) The alkalies dissolve the pulp, which may be pressed out 
easily, so that having tied the nerve and filled it with mercury or air, 
and dried it, the canaliculated structure becomes apparent. On the 
contrary, the acids destroy the sheath and harden the fibres, the finest 
of which then become visible to the naked eye. 

§ 149. The nerve then is composed of two substances, a medullary 
portion and the canals- which inclose it. These canals are formed of 
mucous tissue, and are called neurilemma, a term derived from their 
relation to the medullary substance. The neurilemma envelopes the 
whole nerve, and generally we can suppose it furnished internally with 
folds which continually diminish. It receives numerous vessels which 
divide, at right angles, into two trunks, one straight, the other retro- 
grade ; these frequently anastomose together. 

The neurilemma is very firm and difficult to tear. It appears to be 
the secretory organ of the medullary, with which its relations diminish 
at the two extremities of the nerves. Near the central termination it 
disappears within the nerve sooner than on the surface, so that the col- 
lection of the neurilemmatous canals forms a considerable depression 
towards the brain and spinal marrow. 

§ 150. Besides the fibrous structure of the nerves and their forma- 
tion by two substances, the pulp and neurilemma, and the irregularity of 
form which results from this circumstance, their external surface is 
banded and undulated, and hence appears uneven. (2) By the naked 
eye we observe on the surface of the nerve, and with a microscope, in 
the cords which compose it, spiral bands which are directed obliquely 
in zigzag. This appearance vanishes when the nerve is extended, 
but is again perceptible when the extension ceases. It disappears 
entirely in the morbid state, or at least in nerves softened or decayed, 
either from maceration or from the effect of alcohol. It doubtless 
depends on a folding which takes place when the nerve shortens, on 
account of its slight contractility. It is principally seated in the neu- 
rilemma, for it is not well marked in those nerves which are soft, and 
those furnished with a feeble sheath, as the olfactory nerve. (3) 



(1) Reil, De structura nervorum, p. 3-17. — Osiander, Epigr.in compl. musei anat. 
res., Gottingen, 1807, p. 51. 

r (2) Molinelli, Comment. Bonon., vol. iii. p. 280. — Fontana, Sur la structure des 
nerfs; in his Obs. sur les poisons, vol. ii. — Monro, he. cit. chap. 12, 13. — Arnemann, 
loc. cit. p. 147-174. 

(3) Prevost and Dumas have published some observations on the structure of the 
nerves, which we shall here mention. They state that the nerves have a satinlike 
appearance, which was first completely and exactly described by Fontana. It is very 
smooth, especially in the nerves of the cat, rabbit, guinea pig, frog, &c. When 
examined with a magnifier of ten or fifteen diameters only, we then see on their 
surfaces alternate white and dark bands, which frequently resemble the turns of a 
spiral spring which might be placed under the neurilemma. This appearance, like that 
of the tendinous tissues, depends on a slight folding of the fibres of the neurilemma, 
which loses its transparency in some parts, and retains it in others. Those which are 
opaque reflect all the light which strikes on their surface, and the others on the 
contrary allow it to pass in sufficient quantity to render visible the colored bodies 
placed under the nerves. When we attempt to draw it out, all this appearance 



158 GENERAL ANATOMY. 

§ 151. All nerves are not formed exactly after the same type, and 
probably the modifications observed in this respect depend on differ- 
ences in their mode of action. These differences relate to their inner 
structure and their configuration or external form. 

Modifications of the inner structure may depend either on the medul- 
lary substance, or the neurilemma ; but it is probable that in most 
cases both are concerned. They are — 

1st. Differences in solidity and hardness. Generally, the nerves 
which go to the heart, the large vessels, and to the abdominal viscera, 
the auditory, and particularly the olfactory nerves, are much softer than 
the others. We find scarcely a trace of the neurilemma in the olfactory 
nerve. On the contrary, the fasciculi of the optic nerve are, proportion- 
ally speaking, much larger than those of the other nerves. Very pro- 
bably, then, this difference depends not only on the greater or less con- 
sistence of the medullary matter, but also on the arrangement of the 
neurilemma. 

2d. Differences in color. The nerves of the heart and abdomen, 
and the olfactory nerves, are mostly reddish, and not white like the 
others. There is even a gray substance in the centre of the olfactory 
nerve. 

3d. Differences in the arrangement of the nervous cords and fila- 
ments. Their size varies, but not in proportion to the volume of the 
nerves. The cords of the principal nerves of the inferior extremity, for 

vanishes, and if we divide the neurilemma we find nothing resembling it. It would 
not then deserve notice if it did not offer a very certain mark to recognize the small 
nervous filaments, and render it easy to distinguish them from the blood-vessels or 
the lymphatics. But when we take a nerve, and, dividing its neurilemma longitu- 
dinally, draw out the pnlpous matter under water, we find it composed of numerous 
small parallel filaments of equal size, and which seem to be contained in the whole 
nerve. At least we never see them unite or divide, whatever part we examine. 
These filaments are flat and composed of four elementary fibres, arranged in nearly 
the same level, whence they appear like a ribbon. They are also formed of globules, 
aa usual, and are curious, as the two external are most apparent. The middle 
range is observed occasionally, doubtless, because the pressure it experiences causes 
the line traced by the globules of which it is composed to disappear. The number 
of these secondary nervous fibres is very great, as is seen by the following calcula- 
tion, even when the results of experiments are not strictly regarded. Let us suppose 
that each nervous fibre occupies one thirtieth of a square millimetre of a section of a 
nerve, we have 90,000 for each square millimeter. But we know that the secondary 
nervous fibres include four elementary fibres. We should then find 22 500 in the 
same space, or about 16,000 in a cylindrical nerve of the diameter of a millimeter 
See their Memoire sur les phenom. qui accomp. la contract, de la Jib muse in the 

Journ. de Physiologie Experimentale, vol. iii. 1823, p. 301. P. T.* 

* In regard to the composition of the nerves, M. Raspail, from recent microsco- 
pical observations, asserts, "that if a filament from a nervous trunk be examined by 
the microscope, the trunk is seen to consist only of an agglutination of cylinders, 
the 50th part of a millimeter in diameter." Fontana has proved that these cylinders 
are composed of a smooth and transparent membrane, containing within "a glutin- 
ous, transparent, and elastic matter that does not dissolve in the water in which the 
cylinders float." Having pressed out this matter between two glasses he caused 
it to return again by diminishing the pressure. M. Raspail considers each of these 
cylinders as a cellule which has grown only in length. It incloses a true cellular 
tissue, imbued with a homogeneous and fatty substance. It has no longitudinal 
cavity, and its growth extends itself from the encephalon to its extreme ramifica- 
tions. Am. Med. Jour., Nov. 1828, from the Repertoire d'Anatomie &c 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 159 

instance, are always finer than those of the superior, although the 
nerves of the latter are larger than those of the former. The laryngoeal 
nerve appears as one fasciculus, on which are numerous furrows, which 
indicate the smaller cords, and it is surrounded externally only by a tis- 
sue composed of fine filaments. In some nerves, as the median nerve 
and the sciatic nerve, the size of all the cords is nearly the same. In 
others we see the large cords alternating with those which are very 
small. The anastomotic structure, so apparent in most of the nerves, 
is not observed in the optic nerve which is composed of straight separate 
cords, which proceed one at the side of another ; these cords do not di- 
vide in turn into others which are smaller, so that we may consider 
them filaments as well as fasciculi. 

In regard to figure, the nerves are generally similar in their round 
form ; nevertheless, the olfactory differs from all others, as its shape is 
triangular. 

Most nerves resemble long trunks, which give off branches along 
their course, and gradually divide into smaller trunks. The cords and 
fasciculi consequently are united here. Another arrangement is seen 
in the nerves of the abdomen, where the fasciculi and cords are sepa- 
rated from each other ; so that the trunks which are formed, when com- 
pared with their branches, are not very thick. This difference must be 
ascribed partly to the difference in the form of the regions to which 
the nerves proceed, since the trunks of the extremities are the longest 
of all, and those of the head and trunk are much shorter ; and it must 
doubtless be ascribed also partly to the general law, which is, that the 
organisms and organs of an inferior character are, as a whole, less cen- 
tralized than the organs and organisms of a superior character. 

§ 152. The large or small collections of fibres of which the nerves 
are composed, do not remain united ; but the nerves ramify in their 
course, as their fibrous fasciculi separate. The trunks divide into 
branches, and these into twigs, &c. The branches are generally given 
off at acute angles. But the cords and filaments which unite to form 
a secondary division, are always separated within the trunks much 
higher than they seem to be when we examine their surfaces only. -In 
this arrangement the nervous and vascular systems differ' greatly. It 
is not strictly correct to say, that the structure of the nerves differs from 
the arrangement of the vessels, because the cords and filaments which 
constitute a trunk or a branch of a nerve partially retrograde, as there 
is something analogous in the arrangement of the branches and ramus- 
cules of the vessels. But the nerves differ from the vessels because their 
trunks sometimes run a long space without dividing, while the vessels 
ramify every where and at short intervals, except in a few instances, as 
the spermatic vessels, which in fact prove nothing, since this arrange- 
ment exists because, at a certain period of life, the vessel is inclosed in 
a small space. 

§ 153. The fibrous and anastomotic structure is seen not only within 
the nerves, but is apparent also at their origin and in their course. 
Many nerves anastomose differently together. 



160 GENERAL ANATOMf. 

There are three kinds of anastomosis : 1st, anastomosis, properly 
so called, or union in a web, {ansa); 2d, the plexus; and 3dly, the 
ganglion. 

Anastomosis is formed by isolated branches of different nerves, 
which have nearly the same size. In this manner, for instance, the 
ulnar and the median nerves unite in the hand ; the spinal nerves, 
shortly after, leaving the vertebral canal, the different branches of the 
fifth pair, the branches of this nerve, with the facial and cervical nerves. 
In this manner also the ansa are formed around the vessel. Anasto- 
mosis occurs : 

1st. Between the different branches of the same nerve, as is seen in 
the fifth pair, those of the facial, laryngoeal, and intercostal nerves. 

2d. Between two branches of different nerves, situated, however 
on the same side, as between two spinal nerves, or between the branches 1 
of the spinal and the intercostal nerves. 

3d. Between two branches of synonymous nerves on each side, as 
the superficial nerves of the fifth and seventh pairs, and the nerves of 
the neck. 

§ 154. The plexus(l) is, properly speaking, only an anastomosis be- 
tween the different cords of the same or of different nerves. The cords 
divide into very minute branches, and the filaments which come from 
this division give rise to very numerous anastomoses between different 
nerves ; so that the new nerves, which come from the plexus, are 
formed of filaments derived from many different trunks. The pneumo- 
gastric nerve, before it enters the lungs, is an instance of a plexus 
formed by different cords, coming from the same nerve. The plexuses 
formed from different nerves occur in the nerves of the upper and 
lower extremities particularly. 

One cannot admit the difference between the plexus and anastomo- 
sis, mentioned by Bichat, when comparing the communication be- 
tween the filaments of the facial nerve, and of the fifth pair with that 
between the spinal nerves, by saying, that in the former there is an in- 
timate mixture, a perfect fusion or identity, while there is only a simple 
propinquity, a simple juxtaposition in the second ; for there is as much 
fusion and mixture in both ; but in the latter, the branches which unite 
are smaller and more numerous. 

§ 155. The structure of the ganglions is more Complicated than that 
of the plexus, and their destination is probably different. Their exist- 
ence seems to be more independent than the plexuses ; they appear 
to be distinct bodies, much larger than the nerves with which they are 
united, while the plexuses are simple communications which intimately 
connect adjacent nerves, but do not increase their substance. 

The ganglions(2) have no general and regular form ; in different 
persons they vary exceedingly in size, form, attachment, and even in 

(1) Scarpa, De nervorum gangliis el plexubus, 1779. 

(2) Haase, De gangliis nervorum, Leipsic, 1772.— Kwiatowsky, Theses anal, 
phys. de nervorum decussatione et gangliis, Konigsbcrg', 1784.— Weber, De systemale 
nerveo organico, Leipsk, 1817.— Wutzer, De corporis humani gartgliorumfabricd 
atqueusu, Berlin, 1817. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 161 

existence, since large ganglions are sometimes entirely deficient. 
Most of them, however, are rounded, a little flattened, smooth on the 
surface, situated very deeply, and surrounded with an abundance of 
cellular tissue. They are somewhat hard, and of ordinary color. 
When we open them, we see they are homogeneous masses, having no 
determinate structure. In all their qualities they singularly resemble 
the lymphatic glands. The substance of which they are composed is 
always closely surrounded with a peculiar thin membrane formed of 
mucous tissue, and very abundant in vessels, over which there is 
either a loose cellular tissue, or a fibrous capsule, a continuation of the 
dura mater spinalis. Nerves arise from the ganglions. 

When the nervous ganglions are macerated, they can be resolved into 
two substances, viz. into convoluted filaments, which are continuous with 
the nerves attached to the ganglions, and a grayish red, gelatinous, saltis 
mass, which fills the spaces between the filaments, and also envelopes 
them. According to Scarpa(l) the latter substance is oily, and even 
pure fat in gross people. Bichat(2) was mistaken in saying that fat 
is never formed in the ganglions. 

The substance of the nervous ganglions is very vascular. 
§ 156. The ganglions may be divided into simple and compound. 
The former are developments of trie filaments of one nerveonly,and com- 
municate with no other. The compound, on the contrary, are the cen- 
tral and connecting points of several nerves. They differ too from each 
other in more than one respect. 

§ 157. The form and situations of the simple ganglions are constant. 
They are never deficient, and are found near the origins of the spinal 
nerves, and belong to their posterior roots. Their envelope and sub- 
stance is firmer than those of the compound ganglions. Their exter- 
nal capsule continues with the dura mater spinalis, and the internal 
with the spinal portion of the pia mater. Although the filaments of 
these ganglions ramify, and anastomose very extensively, yet they 
have all the same longitudinal direction. Nerves arise from them only 
in the two opposite points, viz. from the inside arises that portion of 
the posterior root of the nerve which is between the ganglion and the 
spinal marrow, and from the outside, the external nerve_, which soon con- 
nects itself with the anterior root. (§170.) 

§158. The compound ganglions exist in every part of the body, but 
are found principally in the thoracic and abdominal cavities, more par- 
ticularly in the latter. They are softer than the simple ganglions ; their 
external envelope is formed by the surrounding cellular tissue. They 
vary in form, situation, and number. Their constituent fibres do not ex- 
tend from one extremity to the other, but proceed in all directions. Fi- 
nally, nerves emerge not only from their two extremities, but from va- 
rious points of their surface. The filaments never come from the points 
where other nerves enter ; hence these same filaments are never inter- 
cepted at very acute angles. 

(1) Loc. cil.p. 16. 

(2) General Anatomy t vol. i. p. 259. 
Vol. I 21 



162 GENERAL ANATOMY. 

§ 159. The fibrous structure and the intercrossing of the nerves 
are also found in the brain and spinal marrow ; but here they are less 
evident than in the nerves. At first, the brain and spinal marrow seem 
formed only of a soft, pulpy, and homogeneous mass ; but the fibrous 
structure should not be denied on account of this appearance, as has 
been done by several anatomists.(l) 

We have no need of mechanical or chemical agents to observe in 
many places distinct fibres, especially in those brains which are firmer 
than usual. Thus they are seen in the corpora pyramidalia of the me- 
dulla oblongata, the crura cerebri, the corpora striata, the corpus cal- 
losum, the tuber annulare, the commissures generally, and in the for- 
nix. We have even distinguished them on cutting into the mass of 
the hemispheres. But those who admit their existence in several parts 
of the encephalon, say it is not certain that the structure of the whole 
organ is fibrous, or at least they allow it only in certain cases. (2) 

Others, who admit the existence of these fibres after death, regard 
them as produced by the coagulation of the cerebral substance, which 
they consider pulpous during life ;(3) consequently these two opinions 
are similar. Malpighi was the first to demonstrate the fibrous structure 
of the brain, and to describe in what manner its fibres come from the spi- 
nal marrow. But the principal writers uu this part of anatomy are Gall 
and Reil ; the latter, especially, has rendered a very important service 
to science in making known the structure of the spinal marrow,(4) 
which, before his time, had been regarded as a shapeless, pulpy mass, 
even by those who admitted the fibrous structure of the brain. 

Those who admit the fibrous structure of the brain, differ'in opinion 
whether this structure be peculiar to the medullary substance or 
whether the cortical substance also be fibrous. 

Those who admit fibres in the medullary substance, deny that they 
exist in the cortical ; as Malpighi, Haller, and Soemmerrin°\ The 
cortical substance, however, is truly fibrous. In dissecting some very 
firm brains, we have often observed, not only the phenomenon remarked 
by Stenson(5) and Vicq d'Azyr,(6) viz. that the delicate fibres of 
the medullary substance may be followed into the cortical portion but 
also that the latter is evidently fibrous in its structure. 

The fibrous structure of the brain is demonstrated by another cir- 
cumstance ; that the fibres are always arranged in the same manner 
however various are the means used to demonstrate them. 

§ 160. The spinal marrow makes the transition from the nerves 
to the brain, since it is, like the latter, inclosed in a bony case en- 
veloped by the same membranes, communicates directly with it ' and 

(1) See Bichat, Anat. descrip. vol. iii. p. 96., where he goes so far as to ascribe the 
transverse fibres of the corpus callosum to a slight laceration by the knife 

(2) Haller, De part. vol. iii. p. 48.— Soemmerring, Nervenlehre, p. 29. 
(3^ Ackermann, Ueber die Gall'scke Schddellehre, § 6. 

(4) Dc cerebro, Amsterdam, 1669, p. 8-10. 

(5) Disc, sur Vanat. du cerveau, Paris, 1669. 

(6) Mem. de Vac. des sc. 1781. p. 511. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 163 

at first view has a soft and pulpy appearance ; but in texture it resem- 
bles the nerves. It is closely surrounded with a membrane formed of 
mucous tissue and of vessels, which resembles the neurilemma, but is 
called the pia mater, on account of its intimate union with it, or 
the vascular membrane, from its numerous vessels. A simple pro- 
longation is detached from the centre of the internal face of the an- 
terior part of this membrane, which goes inward and backward, and 
penetrates to the centre of the spinal marrow. Numerous small chan- 
nels arise from each side of this prolongation, which pass through the 
whole spinal marrow, anastomose frequently together, and are visible, 
especially when the medullary substance has been destroyed by an al- 
kaline solution. This structure is also seen when the spinal marrow 
is hardened by immersion in an acid, for it is then divided into nume- 
rous longitudinal layers, formed in their turn of very fine cords. 
Sometimes it is observed in the spinal marrow in its natural state, when 
its twoportions are gently separated ; and it may be distinguished also on 
the surface of this organ if it be naturally firm, and its pia mater be re- 
moved. The channels are smaller in the gray than in the medullary 
substance, and are limited suddenly by it. 

The internal structure of the spinal marrow is then more analogous 
to the nerves, although it is softer and its fibres are less apparent.(l) 

§ 161. The spinal marrow is composed of two lateral parts, which 
are separted from each other before, by the prolongation of the pia ma- 
ter above mentioned. Towards the upper part of this organ, near 
where it enters the skull, its cords divide into several fasciculi, which 
cross obliquely, so that those from the right side pass to the left, 
and vice versa. At the same time, these are enlarged by the ad- 
dition of several masses of gray substance. On the sides are detached 
the crura cerebelli, or corpora restiformia, which develope and give rise 
to the cerebellum. Before and above are perceived the pyramidal 
bodies, (corpora pyramidalia,) two oblong eminences placed near 
each other, on the under face of the upper extremity of the spinal mar- 
row. These pass over a large projection formed of transverse fibres of 
cortical and medullary substance called the pons varolii, or annular 
protuberance, (nodus cerebri,) and penetrate the inferior face of the brain, 
where their fibrous structure becomes apparent by the separation of their 
medullary substance, in the interstices of which the gray substance 
extends. Being now much enlarged and divergent, they pass before 
the pons varolii, and produce the peduncles of the brain, (crura cerebri.) 
These pass below and across the two masses of gray substance, situated 
one at the side of the other, called the thalami optici, and before which 
are formed the corpora striata; after this, their fibres, becoming 
very apparent, unfold in all directions in the cerebral hemispheres, of 
which they form the principal part, and extend circularly ; this radia- 
tion of fibres from the gray substance is called, by Reil, the corona 
radiata (stabkranzes).(2) 

(1) Scemmerring, Nervenlehre, p. 62-63. 

(2) Reil, Archiv., &c. vol. ix. P. 1. p. 159. 



164 GENERAL ANATOMY. 

§ 162. The two lateral portions of the spinal marrow and of the 
encephalon are not only placed close to each other, but are attached 
by medullary fibres, and gray substance. The places where they are 
connected may be termed by the general name of commissures. These 
commissures are every where narrower than the parts which they 
unite. If examined attentively, they can be traced in each part 
much farther than one would suppose at first view. As the fibres de- 
scribed in the preceding paragraph are longitudinal, while those of the 
commissures are, on the contrary, oblique, Gall(l) considers them as 
forming a peculiar fibrous apparatus, and admits both in the cerebrum 
and in the cerebellum, an order of diverging, and one of converging 
fibres. These two orders have been more physiologically termed the 
first, the apparatus of formation, the second, the apparatus of union. 
They are also named from the parts they concur to form ; the first, 
the system of the cerebral peduncles ; the other, the system of the corpus 
callosum. The fibres of these apparatuses differ, not only in their direc- 
tion, but in their origin, position, and consistence. In fact, while the 
diverging fibres terminate at the external surface of the encephalon in 
the gray substance, the recurrent fibres arise from the gray substance and 
proceed on the median line, where they unite by commissures of greater 
or less extent. We cannot consider these unions themselves as origins 
of the recurrent fibres ; for it is a general law, that the medullary sub- 
stance arises from the gray substance, and the commissures extend 
some distance beyond the two cerebral hemispheres. The fibres of 
this system are placed between those of the diverging system, and 
consequently much more internally. They are much softer and finer 
than the latter. They form distinct layers, which envelope the cerebral 
ventricles. In admitting this second system which arises from the gray 
substance deposited on the surface of the encephalon, we explain how 
the two parts of the organ inclose more of the nervous mass than the 
corpora striata, so that they appear only as an appendage or appurte- 
nance of these parts. 

We cannot determine with precision how the two systems unite. 
Even Gall admits that we cannot ascertain whether the fibres of the 
diverging mass are reflected in the gray substance, and change their 
direction, and thus produce a new recurrent nervous system, or if the 
latter be really a separate body, which does not arise from the former. 
Reil, who does not appear to admit a single system of commissures con- 
nected in all parts, since he describes the structure of the corpus callo- 
sum separately from that of the anterior commissure of the brain, and no 
where informs us that their expansions are connected, Reil, we say, 
thinks the two systems are not in every part united in the same 
manner. He only states generally in regard to the union of the radi^ 
ating fibres of the anterior commissure with those of the cerebral pedun- 
cles, that they form a whole, but he believes the modes of union be- 

(1) Gall On the anatomy of the nervous system, Paris, 1809.— Ibid. On the anato- 
my and physiology of the nervous system, Paris, 1810. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 165 

tween the radiations of the corpus callosum and that of the cerebral 
pedunc es are numerous. In fact, we find between them and forward, 
a medullary substance less evidently fibrous, which unites them Far- 
ther back the two systems anastomose ; and still farther, their fibres 
reciprocally penetrate each other, and intercross several times forming 
a delicate suture ; finally, the most posterior part of the corpus callo 
sum passes above the system of the cerebral peduncles without uniting 
to it, and gives origin to two separate masses, which may be entirely 
detached from each other.(l) y 

§ 163 The structure of the brain differs from that of the nerves 
principally m two respects : 1st, its constituent fibres mostly form 
ayers ; 2d, we find no neurilemma within it. Its fibres are loose and 
he surface of the brain is covered only with a capsule analogous to 
he neurilemma, which, as in the spinal marrow, is called the pia ma- 
w w n f ml ^ mmatlc tubes do not exist, even in those parts 
which, from their form, are usually considered as nerves ; as that part 
of the optic nerve situated behind the place of crossing, and the olfac- 
Z 7 tnfT\ hUS /^ consid er the olfactory nerves as making a 
part of he brain itself, and very properly regard their branches alone 
as constituting so many distinct olfactory nerves. Besides the absence 
of neurilemma, the form of the nerve, its gray mass and the swelling of 
its round extremity which resembles a ganglion, are so many circum- 
stances m favor of this opinion. The same remarks apply to the inner 
part of the optic nerve, which would then arise only at the place of 
crossing. r ^ 

The arrangement of the pia mater, however, and its relations to the 
cerebral substance also establish an analogy between it and the neu- 
rilemma. On one hand, the external surface of the brain is folded at 
least partially, in certain animals ; and every where in man and in 
most mammalia, has circumvolutions (gyri) and furrows (sulci) situ- 
ated between them, by which the pia mater penetrates to the internal 
surface of the brain, into the ventricles, where the choroid processes 
{processus chorotdei) form, and numerous vessels enter, especially 
in certain uniform places, into the internal part, and may there 
be recognized on examination, not only by red points in consequence 
of the blood which flows out when they are cut, but may even for a 
short distance be drawn out freely from the soft parts. On the other 
hand, several parts of the brain resemble the nerves, both externally 
and internally : such as, for instance, the anterior commissure which is 
surrounded by a cellular sheath furnished by the pia mater of the ven- 
tricles ; this sheath accompanies it in its course across the thalami 
optici and is changed, like the neurilemma, into a delicate cellular tis- 
sue, and disappears only at that part where the extremities of the com- 
missure expand into a radiated tissue.(2) Perhaps, then, the struc- 

t£lJr^t r c f, current . fibres of ^e brain are not admitted by Tiedemann, who considers 

(2, Reil, Archiv. vol. xi. P. i. p. 91. ' V ' 



166 GENERA I. ANATOMY. 

ture of the brain is every where the same as that of the nerves, 
but the softness and fineness of the mucous tissue prevents its demon- 
stration. 

§ 164. From the above remarks it follows, that the brain and spinal 
marrow are formed of fibrous fasciculi differently intermixed ; -that these 
fasciculi are perceived more easily in the medullary than in the gray 
substance, and that their connections are more or less evident. It fol- 
lows, then, that the nervous mass contained in the skull and vertebral 
canal is formed, essentially, after the same type as that formed in the rest 
of the body, and that the principal difference between the two masses is, 
that the first is accumulated in one part, ivhile the second is more dif- 
fused. 

§ 165. The gray substance does not form, like the medullary sub- 
stance, a continuous system. According to several anatomists(l) the 
neurilemma supplies the nerves with a gray substance, because these 
are not so white as the cerebral substance, and become more volumi- 
nous as they leave their centre. But these two circumstances are not 
sufficient to establish the opinion in favor of which they are adduced, 
although this opinion is probable to a certain extent, as it increases the 
analogy between the brain and nerves. That it should be more than 
probable, it is requisite that the pia mater should no where possess the 
direct power of producing the medullary substance, but it really does 
possess it in several points of the encephalon, and in all the spinal mar- 
row. So little does the gray substance represent in the brain a con- 
nected whole. The gray substance, it is true, forms an uninterrupted 
layer over the whole surface of the cerebral organ, but it does not com- 
municate with the nerves of the same substance within this vise us, nor 
can we demonstrate an uninterrupted communication between these lat- 
ter.(2) Some anatomists admit, also, a sort of communication depend- 
ent, 1st, on the vessels, as the cortical substance is entirely vascular ; 
2d, on the communication between the internal portions of the thalami 
optici with the corpora striata, the tubercula quadrigemina with the 
other parts of the encephalon, and the medulla oblongata with the pons 
varoki :(3) but the truth is, that a layer of medullary substance exists 
every where between the gray substance of the thalami optici and 
that of the corpus striatum,(4) and that the gray substance of the pons 
varolii and of the olivary bodies does not communicate with the distant 
masses of this same substance. (5) 

The gray substance diffused in the body by the ganglions, is like- 
wise insulated. The mass of this substance within the brain 'and ge- 
nerally in all the central parts evidently corresponds to that which ex- 

(1) Battie, Exerc. deprinc.anim., p. 156. 

(2) Munro, On the nervous system, chap. 10, § 25. 

(3) Ludwig, Decinered cerebri substantia. Lcipsic, 1778 d 11 §2 

(4) Wenzel, loc. cit. chap. 6. > f , , i>- , ? *~ 

(5) Vicq-d'Azyr, loc. cit., an. 1781, p. 507. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 167 

ists in the ganglions.(l) When man is fully developed, the quantity 
of the medullary substance is much greater than that of the cortical. 

§ 166. The inner ends of the nerves communicate with the central 
parts of the nervous system. The fasciculi which form them there 
separate more or less distinctly, proceed without communicating to- 
gether, and enter the cerebral substance ; but we cannot distinctly per- 
ceive where the fibres of the two unite. 

Two questions arise as respects the origins of the nerves. With what 
substance of the central part are they connected ? Do the origins of 
the synonymous nerves communicate, or do they arise from sides oppo- 
site to where they are distributed, so as to intercross ? 

§ 167. In regard to the first point, the most general opinion is, that 
the nerves arise from the medullary substance ; that they radiate' from 
it and are prolongations of it. (2) It has even been conjectured that 
in the spinal marrow this substance is placed externally, so that the 
nerves which come from it pass over less space, and are not obliged to 
penetrate through the gray substance.(3) Nevertheless, when closely 
examined, all the nerves are seen to communicate more or less evi- 
dently with the gray substance. Vicq d'Azyr had ascertained this 
fact, as he says that the gray substance is generally accumulated near 
the origins of the nerves.(4) Gall has added his testimony in favor of 
it, and we are satisfied from our observations that he is perfectly correct. 

This fact is incontrovertible in regard to insects, worms, and fishes' 
where the nerves arise by several roots from the mass of gray sub- 
stance. It is evident, also, in some nerves of the superior animals and 
of man, for instance, in the olfactory and optic nerves. It is more dif- 
ficult to prove it in regard to the other nerves, which, at first view seem 
connected only with the medullary substance ; but we must carefully 
distinguish the place where the nerve detaches itself from the central 
mass, from that where it arises. (5) Although in the first of those two 
points, which is external to the central part, most of the nerves com- 
municate with the medullary substance only, and several, as almost 
all of the cerebral nerves are so feebly attached to it, that they may be 
easily separated from it, whence we might infer they arise from it ■ we 
can, however, follow them farther, and at a certain depth, sometimes 
their bundles unite in a cord which communicates with the gray sub- 
stances, as takes place for instance, in the fifth pair ; sometimes their 
filaments come from this same substance separately, as is the case 
with all the spinal nerves. 

(1) This is intended for Haller, who says expressly : In homine et quadrupedibus 
qua. mihi innotuerunt, in nervis ipsis ejusmodi noduli unice reperiuntur neque in 
cerebrounquam aut in spinali medulla. (De -part. corp. hum. fab vol viii'p 322) 

(2) Haller, De part., vol. viii. p. 319. Principium nervorum ' communisensu in 
meaulta est encephah et spinalis medulla:. 

(3) Martin, De nervis corp. num., Halle, 1781, p. 27. 

(4) hoc. cit., p. 508. 

(5) By origins of the nerves, we commonly understand that portion between the 
place where they arise from the central mass and that where they emerge from ths 
ekull. But this term is too inconvenient to be long retained. 



168 GENERAL ANATOMY. 

Although in man and the superior animals, all the parts of the spi- 
nal marrow, from whence nerves arise, are not enlarged by the accu- 
mulation of the gray substance, as Gall pretends, yet we cannot deny 
but that this substance exists in greater quantity at the origins of the 
large nerves. Hence its greater volume at the origin of the nerves 
which go to the extremities. 

§ 168. But although we should seek the origin of the nerves be- 
yond the surface of the central mass, we have no right to believe it 
deeper than we can trace it, and to consider all the nerves as arising 
from a single point of small extent ; an opinion maintained by those 
who are disposed to consider the medulla oblongata as this common 
origin. 

§ 169. Do the nerves arise from the same side of the body as 
that to which they are distributed ? Do the synonymous nerves unite 
or cross each other 1 or do we find both union and crossing 1 All these 
problems have been resolved, sometimes negatively and sometimes 
affirmatively. Throwing out of view the fact that all observations 
have not been made with the same exactness, the difference of opinion 
in this respect depends on this, that the arrangement of the parts is not 
the same in all animals. The interlacing of the nervous fibres has 
been supposed, from the paralysis of one side of the body, when the 
opposite side has been injured.(l) But we learn from dissections, both 
in the normal and abnormal states, that these observations and experi- 
ments demonstrate only the crossing of the spinal marrow at the point 
mentioned above, (§ 161,) and do not prove that all the nerves arise 
from the half of the brain or spinal marrow opposite to that side of the 
body in which they are distributed. Although we have often followed 
the spinal nerves into the gray substance, we have never observed a 
single filament passing to the side opposite. Injuries of the central por- 
tion are not followed by a paralysis of the opposite side of the body, 
when they affect a part above that where the intercrossing, of which 
we have spoken, takes place. This paralysis of the opposite side 
occurs when the medulla oblongata is injured,(2) but not when the 
parts below are affected ; for then it supervenes on the same side 
as that where the section of one half of the spinal marrow has been 
made. Galen was acquainted with this difference in the consequences 
of the injuries of the brain and spinal marrow. (3) Even when one 
half of the spinal marrow is cut near its upper part, paralysis takes 
place only on the corresponding side, as is proved by recent experi- 
ments. (4) 

(1) Hippocrates, Epid., Book vii. § 1.— Valsalva, in Morgagrii, Ep. vol. xii. p. 14.— 
Prochaska, Obs. path, in Opp., Vienna, 1800, vol. ii. p. 298-320. 

(2) Yelloly, A case of tumor in the brain, with remarks on the propagation of 
nervous influence; in the Med. chirurg. trans, vol. i. xvi. p. 181-222. A tumor a3 
large as a nut on the left side of the pons varolii and of the left pyramid, produced 
a paralysis of the right side. 

(3) De anat. administr. vol. viii. p. 5, 6. 

(4) Yelloly, loc. cit., p. 197. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 169 

No interlacing 1 , either in the brain or spinal marrow, can be demon- 
strated, except that which exists in the place indicated above. Obser- 
vations and experiments, from which it has been concluded that fibres 
cross each other principally in the corpora striata(l) prove nothing. 
Besides the proposition contradicts itself, since the corpora striata are 
not connected with each other ; nor does the anterior commissure, 
which passes through them, communicate either with their proper 
substance, or with the fibres which enter them. From these observa- 
tions we can only observe, that the fibres cross below the corpora 
striata, as we have proved above. 

Still a partial communication takes place between some of the 
nerves, as their external filaments arise from one side, and their inter- 
nal from the side opposite. This arrangement however has been ob- 
served only in the optic newe. 

Nor can we demonstrate that the origins of all the nerves unite on 
the median fine, although this union is sometimes observed between 
the corresponding nerves of the fourth pair, and the auditory nerves. 
Probably this is not rare, especially in the spinal nerves. 

§ 1 70. The origins of all the nerves are similar in one respect, that 
the fasciculi which form them separate from each other in those 
places (§ 147). But the spinal and cerebral nerves differ constantly 
from each other in their mode of origin from the central mass. 

In fact the cerebral nerves arise by a single root, wnile the spinal 
nerves have two, a posterior and an anterior, corresponding to the ante- 
rior and posterior faces of the spinal marrow. Nevertheless, we see 
that the nerves of the brain (commencing at the fifth cerebral nerve) 
resemble those of the spinal marrow by the division of their fasciculi 
into two parts. The posterior roots are always larger than the an- 
terior, and usually arise nearer the centre of the spinal marrow ; but 
their fasciculi are fewer and less evidently fibrous, single, and do not 
ramify, while the anterior come from the medulla by numerous rami- 
fications. The two series of the anterior and posterior roots are sepa- 
rated by a prolongation of the tunica arachnoidea, called the ligamen- 
tum denticulatiim, which goes from the lateral face of the medulla to 
the corresponding part of the internal face of the dura mater. 

The fasciculi of each nervous root are also remote from each other 
until they leave the dura mater spinalis, and are connected only 
by a looser mucous tissue. But arrived at the dura mater, they reunite, 
and each root emerges by a single foramen, formed by this membrane. 
The foramina of the anterior and posterior roots are near each other, 
but always separate, and the roots unite in a single nerve only after 
traversing the dura mater. 

On the contrary, the fasciculi which form the cerebral nerves come 
from the dura mater by a single opening, although at the moment they 

(1) L. Caldani, Esperienze ed. osservaz. dirette a determinate qual sia il luogo 
principale del cervello, in cui, piu di altrove le fibre medollari dello stesso viscera si 
incrocicchia.no ; in Mem. di Padova, vol. i. p. 1-16. 
Vol. I. 22 



170 GENERAL ANATOMY. 

arrive at it they are not intimately united, as is seen particularly in the 
posterior nerves. 

The direction of the origins of all the nerves is not the same. The 
cerebral and spinal nerves are totally different in this respect. The 
nerves of the encephalon are all directed forward, those of the spinal 
marrow downward, except the first two, the superior fasciculi of which 
descend, while the inferior ascend. 

The cerebral nerves generally proceed much more directly forward, 
and the spinal form acute angles at the base, which are more acute as 
the first arise farther forward, and the second farther behind. The 
middle pairs, the posterior nerves of the encephalon, and the upper 
spinal nerves, have a more oblique direction. 

We also find, that the filaments of several pairs of nerves communi- 
cate within the dura mater, as is seen especially in the upper spinal 
nerves, and also between the fourth and fifth pairs of the cerebral 
nerves. 

The posterior root of each spinal nerve, shortly after passing through 
the dura mater, becomes a simple, oblong, rounded ganglion, (§ 157,) 
with which the anterior root does not communicatee 1) although, as 
Gall very justly remarks, we sometimes see, especially in the neck, 
the anterior roots forming thick reddish plexuses, which may be con- 
sidered as ganglionary bodies. 

In many cerebral nerves, either in their passage across the dura 
mater, or at some distance from this point, we see analogous bodies, 
which are formed however by all the nervous fasciculi. 

§ 171. The nerves gradually enlarge in their course. In fact they 
always ramify ; and the trunks which arise from the encephalon and 
spinal marrow divide into branches, twigs, and filaments. These are 
given off almost always at acute angles, and rarely at right or obtuse 
angles. But if we imagine all the branches reunited, we shall have 
a cone, the summit of which corresponds to the origin of the nerve, 
and the base to its periphery. This is a general law. The nerves 
which do not give off branches in their course, as the optic nerves, 
the auditory, and also the olfactory nerve, (if the portion of the 
nervous system generally so called, be a real nerve,) are not every 
where equal in size, but sometimes even become thicker, as is seen 
in the last two especially. 

(1) Scarpa is generally regarded as having discovered that the ganglions of the 
spinal nerves are formed only by their posterior root. The honor of this discovery 
is however ascribed to Monroe by Nicolai (De medulla spin. av. Hal. 1811, p. 28); 
but wronarly, since Prochaska states, in his treatise on tine nerves, (1778, p. 139,) 
" Funiculi posterioris principii (nervorum spinalium) soli in ganglium spinale intu- 
mescunt ; antcrioris vero principii funiculi g an glio illi ope cellulosce adhccrentes 
solummodo et prater eundo cum postcrioribus ex ganglio egressis primo conjugun- 
tur," &c. Scarpa's work appeared in 1779, the original of Monroe's in 1783 ; but 
Haase (De gan<rliis nerror. Lcips. 1772, p. 87) says: " Sed hcec, (radix nervorum 
spinalium anteriorly non lota in ganglion inscrebalur, scdpaucis tantum succulisin 
ganglion immisis, major hujus radicis pars ganglion quasi prceteribat, ut nonnisi 
contextu celluloso ganglio leviter agglutinata per foramen vertebrate." Thus the ho- 
nor of this discovery belongs to a German. 



ON THE NERVOUS SYSTEM IN THE NORMAL STATE. 171 

The three branches of the fifth pair are evidently larger than its 
trunk, &c. Some branches also are arranged in the same manner, as 
the nerves of the lips and the cord of the tympanum. This law, 
however, does not depend on the large size of the nerves of some 
organs, as among others of those of the muscles of the eye, for this 
size depends upon the circumstance, that the nerves of which it treats 
are very large, proportionally, at their origin. 

The central mass also enlarges from the inferior extremity of the 
spinal marrow to its termination in the skull, where it produces the 
encephalon. 

§ 172. The relations of situation between the nerves and vessels 
are not every where the same. Some nerves accompany the arteries 
and veins, and this is most usually the case ; we see it in the crural 
nerve, in the median nerve, those of the forearm and leg, the intercostal 
nerve, and those of the abdominal viscera. Others accompany 
the veins only, as the large cutaneous nerves of the extremities. 
Many proceed alone, at least for some distance, as the ischiatic, the 
radial, the ulnar, and the laryngeal nerves. These differences depend 
on those in the modes and places of origin of the nerves and vessels ; 
for 1st, the nerves arise more detached from each other, and more 
directly from the spinal marrow and the encephalon than do the vessels 
from the aorta and the vena cava ; 2d, the central parts of both systems 
are distant from each other, so that the principal rays must pass 
through a certain space before meeting. Hence why the secondary 
branches of the nerves usually accompany the vessels, and why the 
branches of the nerves and vessels enter the organs at the same point, 
while their principal trunks are separated. 

§ 173. The terminations of the nerves are not every where the 
same. The optic nerve differs from all others, as it does not ramify ; 
when it reaches the eye it forms a homogeneous expansion, called the 
retina. Some assert that the structure of the retina is fibrous,(l) but 
the observations on which this opinion is founded are not conclusive. 

On the contrary we cannot deny that the fibres of the auditory 
nerve interlace like a plexus, and terminate in a thin expansion. 
Generally, we cannot discern the terminations of those nerves which 
penetrate to the interior of the organs, and do not form like the pre- 
ceding, a particular layer, but seem rather blended with their sub- 
stance. Nevertheless, the final branches certainly become very soft, 
and consequently, seem wholly or partially deprived of their envelope, 
so that the medullary substance appears to predominate at their 
periphery, as also at their central extremities. This arrangement is 
very important, not only in an anatomical, but in a physiological point 
of view, as it establishes between the two extremities an analogy of 
structure, expressed, even in the external form, by the uniform separa- 
tion of the filaments, while the denudation of the medullary substance, 
in these two points, attests its importance for the reception of internal or 
external impressions. 

(1) Darwin's Zaonomicc, vol. i. 






172 GENERAL ANATOMY. 

The nerves do not probably ramify so much that they are identified 
to a certain extent with the substance of the organs, for microscopical 
observations demonstrate the contrary, even in those organs which 
are very sensible, as the muscles. The finest nervous filaments are, 
however, certainly twelve times ag large as the smallest muscular 
fibres, but the latter are compressed against each other so closely that we 
see them only, and cannot perceive the nervous filaments, or even the 
branches of the vessels, although both are considerably larger than 
the muscular fibres.(l) Probably then the extremities of the nerves 
have an atmosphere by which their influence extends beyond their 
substance. In this manner we can explain how paits, destitute of 
nerves and therefore insensible, when diseased, experience very acute 
sensations. 

§ 174. The nervous system is not connected with all the organs, 
nor does it exist to the same extent in those in which it is found. 
The parts destitute of nerves are the mucous tissue and its semi-fluid 
fat, the serous membranes, the bones with their medulla, the cartilages, 
the fibrous parts, the epidermis and its appendages the nails and the 
hairs, some organs of a peculiar tissue, as the transparent cornea, the 
crystaline humor, and finally certain parts of systems which receive 
nerves in others, as all parts of the ovum, notwithstanding the 
large size of the umbilical arteries and veins. 

Among the organs possessing nerves, the viscera of the chest and 
abdomen are those which receive the smallest and fewest. As they 
are formed principally of mucous membranes and of vessels, we may 
say that the mucous membranes are those parts which possess the 
fewest nerves. 

The vascular system stands a little higher in this respect; the 
arterial system possesses more nerves than the venous and lymphatic 
systems. 

The nerves of the muscles are still larger. But the muscles differ 
greatly in this respect. The nerves of the heart are smaller than 
those of the voluntary muscles, and thus it makes the transition from 
the arteries to these organs. Among the voluntary muscles, the nerves 
of those of the eye are the largest, the others are nearly similar in 
this respect. 

The nerves of the flexor muscles are generally larger and more 
numerous than those of the extensor muscles. 

The organs of sense which must be considered as simple appen- 
dages of the nervous system, are those in which the most nervous 
substance is found. Of these the skin receives the smallest nerves : 
but all its parts are not similar in this respect. Thus the skin of the 
fingers, of the lips, of the clitoris, and of the penis, possesses more 
nerves than in other places. The olfactory membrane of the nose 
and the envelope of the tongue possess still more. The auditory nerve is 
still larger, and the optic nerve the largest of all. 

(1) Fontana, Ueber das Niperngift, Berlin, 1787, § 39 J. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 173 

Further, all the organs of the senses, except the skin, receive nerves 
from different sources. One is the nerve of sense, properly so called, 
which developes itself to give rise to the sensitive apparatus, the other 
is another pair, generally the fifth.(l) The tongue by its structure 
and the arrangement of its nerves, forms the transition, from the other 
organs of sense to the skin ; for it receives branches from several pairs, 
of which one alone is developed in the organ of taste, and that is not 
a distinct trunk, but comes from the fifth pair. . 

§ 175. The iiervous system is supplied with a considerable quan- 
tity of blood. The strictest and most exact calculations estimate the 
blood which goes to the brain of man(2) one-fifth of that in the whole 
system. The nerves also in their course receive numerous vessels which 
are proportionally large. These vessels usually penetrate them 
almost at right angles. Arrived at their surfaces, they divide into 
two branches, an ascending and a descending branch, which curve, 
frequently subdivide, penetrate the tissue of the nerve, and anastomose 
not only with each other, but with the adjacent branches. From the 
frequency of these anastomoses and the numerous vessels of the 
nervous system, the circulation can never be interrupted. This 
arrangement exists in all parts of the system : for each side of the brain 
receives two arteries which anastomose with each other and with 
those of the opposite side, and form a circle of vessels. The arrange- 
ment of the vessels is also peculiar in this respect, that the circulation 
in them is much retarded. This is strikingly seen in the brain where 
all the arteries make numerous and very considerable curves. The 
vessels of the nerves offer something analogous in their division into 
two branches, forming together a right angle. All these vessels 
divide also into very minute branches before penetrating into the sub- 
stance of the nervous system. However, they do not extend very 
deeply into this substance, at least the nerves of the medullary part of 
the brain are not tinged, and hardly change their color, even when 
other parts become entirely red. (3) 

The vessels <af the gray substance, both in the brain and ganglions, 
are more numerous and larger than those of the medullary substance, 
(§. 141.) Even where the latter is external, vessels pass through it 
to expand in the gray substance. Those which come to the latter 
proceed inward, dividing continually until they have attained the 
white substance, when they change their direction, follow that of 
the fibres, and do not give off any more branches. 

The arteries and veins in the nervous system have not the same 
relations of situation as in most other parts. In fact, they do not 
accompany each other mutually ; so that their trunks come from 
entirely different parts of the skull and nerves. The arrangement of 

(1) On this subject see Treviranus, Observations pour servirde complement a P Ana- 
tomic comparee et a, la Physiologie de Vorgane de la vue ; in the Journ. compl, du 
Did. des sc. mid. vol. xvi. p. 331.— F. T. 

(2) Haller, De part. corp. hum. fub. vol. viii. p. 230. 

(3) Prochaska, Disq. organ, corp. hum. an. phys. Vienna, 1812, p. 100-103. 



1*74 GENERAL ANATOMY. 

the veins is peculiar in this respect, that the branches unite to the 
trunks in a direction opposite to that of the course of the blood. They 
have no valves. This arrangement, with that of the arteries, proves 
that the blood in the brain circulates slowly and uniformly. 

The vessels of the cortical substance are also peculiar in this respect, 
that the veins are not more numerous than the arteries, as in other 
organs.(l) Ruysch asserts even that this substance has no veins, 
and that the passage from the arteries to the veins takes place on its 
outer surface, in the pia mater. (2) 

The existence of absorbent vessels and lymphatic glands within the 
brain has not as yet been demonstrated. Pathological phenomena, 
particularly the formation of round tumors in the brains of scrophulous 
subjects, which have been considered as proving the existence of 
lymphatic glands, (3) prove nothing ; for these tumors may be wholly 
new formations, as they are in other parts of the body where similar 
formations are developed. 

§ 176. The nervous system is surrounded with different envelopes, 
which are not alike every where. The most immediate and essential, 
and that which seems most intimately connected with the nervous 
substance, is a membranous layer of mucous tissue, in which the 
vessels expand before they pass into the nervous substance. This 
membrane is the pia mater, the neurilemma, the principal modifications 
of which have already been stated, since its transition from the brain 
and spinal marrow to the nerves is very evident. A thick layer of 
mucous tissue is found immediately above it. The structure of this 
tissue is not fibrous in the nerves ; but it is very strong, and has a 
silvery lustre. It not only entirely envelopes the nerves in all parts, but 
also sends prolongations internally, which surround their several cords. 
Serum and generally fat also are deposited within this cellular layer ; 
it becomes thinner externally, is continuous with the mucous tissue of 
the whole body, and unites the nerves with the parts adjacent. The 
nerves within the skull and vertebral canal are destitute of this external 
and solid envelope ; but the brain and spinal marrow are there sur* 
rounded with two membranes beside the neurilemma. The middle 
lining is the arachnoid membrane, (tunica arachnoidea,) a thin white 
membrane, which is destitute of vessels. This membrane, after lining 
the brain and spinal marrow, sends a hollow prolongation, which 
extends to the opening of the skull or of the vertebral canal, where it 
disappears. 

The third envelope is the dura mater, which takes the place 
of the periosteum, at least in the skull; for it is intimately con- 
nected to the internal face of its bones, while it does not adhere 
to the parietes of the vertebral canal. This membrane belongs to the 
class of fibrous organs. It generally stops at the opening through 
which the nerve emerges from the skull or vertebral column, and blends 

(1) Vicq-d'Azyr, Mem. de Paris, 1783, p. 510. 

(2) 77ies. anat., vi. no. 7:!. 

(3) Reil, Memor. din., vol. ii. pp. 1. 39. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 175 

with the periosteum and the external cellular membrane which covers 
it. The optic nerve alone is an exception to this rule ; since, after 
leaving the skull, until it is inserted into the globe of the eye, this nerve 
is surrounded by a thick and firm membrane, resembling the dura 
mater, and entirely different from the external envelope, which continues 
uninterruptedly with the fibrous membrane of the eye. The external 
or cellular tunic of the nerves has some analogy with the dura mater 
and the two are united. Still the ancient anatomists were wroncr in 
blending them, and in thence admitting that the nerves are enveloped 
by the dura mater, an opinion which Haller (1) and Zmn (2) have 
refuted. 

The ganglions have the same envelopes as the nerves with which 
they are connected. All have an internal cellular capsule, analogous 
to the neurilemma or to the pia mater, in which their vessels are 
expanded, and an external envelop which arises in the compound gan- 
glions from the cellular coat of the nerves, with which it is blended ; 
in the ganglions of the spinal marrow, however, this is the same as the 
dura mater. 

§ 177. The nervous substance possesses to a certain degree the 
power of extending and contracting. But this power does not exist 
in all parts of the system in the same degree. The changes of form 
and volume are every where slow and gradual. 

The dropsy of the ventricles of the brain proves the extensibility of 
the nervous tissue. In this disease the thickness of the brain, which 
is usually several inches, diminishes to a few lines only, and the whole 
organ becomes an immense vesicle. Here we may mention the nerves 
over large tumors, which resemble broad flat bands. 

The nervous substance is contractile • for the nerves which are cut 
across retract, whether they be, or be not organically connected with 
the parts to which they go. 

Elasticity is also a property of the nervous substance. If the brain 
be compressed, it rises when this compression ceases ; a nerve when 
drawn out, lengthens, and when released, returns to its original dimen- 
sions. 

But the phenomena of extensibility, contractility, and elasticity, do 
not prove the irritability of the nerves, as Home asserts ;(3) for the 
contractions observed in experiments on nerves removed from the body 
or still attached to the organs, prove only the existence of the first 
three properties, and not that they possess the fourth. 

All the parts of the nervous system are not alike in regard to sensi- 
bility. Its periphery, comprising the nerves properly so called, is 
highly sensible, and it is even in this that their function consists. This 
power undoubtedly resides in the nervous substance, since the neuri- 
lemma disappears at the extremities of the nerves, and pain is not 

(1) Prim. lin. n. 370. Ue fab., vol. viii. pp. 305, 306. 

(2) De I'enveloppe des nerfs, in the Memoires de Berlin, 1753, p. 130-144. 

(3) On the irritability of the nerves, in the Phil. Transact., 1801. 



176 GENERAL ANATOMY. 

caused by merely exposing these organs, but they must be compressed 
or divided. 

Opinions differ in regard to the sensibility of the cerebral substances. 
Some writers, particularly Lorry(l) and Lecat,(2) wholly denv it; 
others, on the contrary, as Haller,(3) admit it in regard to the deep 
portions of the encephalon, but refuse it to the cortical substance and 
even to the superficial layers of the medullary substance ; finally, 
many assert its non-existence in the deep parts, but admit it in the 
superficial portions. The last hypothesis seems most probable to us. 
It belongs to Boerhaave (4) and Caldani.(5) 

§ 178. Although we have seen above that the masses of gray sub- 
stance do not communicate, still the whole nervous system is every 
where connected, und all its parts communicate with each other in 
different modes. We must now point out the relations between these 
different parts, that is, we must determine, 1st, what are the relations 
between the two substances, and the functions performed by each ; 2d, 
what is the mutual relation of the different parts or the principal sec- 
tions of the nervous system. 

§ 179. The medullary and gray substances have undoubtedly 
important relations with each other, since they exist in all those ani- 
mals which have a nervous system ; but it is difficult to determine 
what these relations are. It is generally thought that the medullary 
substance is connected with the intellectual faculties more intimately 
than the cortical substance, the function of which is to nourish the 
medullary substance, or to secrete a principle which acts in it ;(6) and 
this because it receives so many vessels. The gray substance is sup- 
posed to be the matrix of the medullary substance, 

1st. Because it is generally diffused. It not only covers all the 
extremities of the nerves, and forms, for instance, most of the pituitary 
membrane, the retina, and the fluid in which the extremities of the audi' 
tory nerve and the rete mucosum of Malpighi are placed, but also 
accompanies the nerves in their whole course. 

2d. Because we find it in masses wherever the medullary substance 
exists in greater quantity, and its functions are more important. 

But these two circumstances are not sufficient to prove that these are 
the functions of the cortical substance. It is not proved that the gray 
substance accompanies the nerves in every part, nor that it surrounds 
their extremities ; and if it abounds in the parts where the medullary 
substance is found in excess, it may be designed for an end very different 
from that assigned to it. The -accomplishment of certain vital actions 
may possibly depend on the simultaneous presence, the union, and reac- 
tion, of these two substances. If the hypothesis above mentioned were 
correct, the cortical substance probably would not become more and more 

(1) Memoir e sur les mouv. du cerveau, in Mem. pres., vol. ii. p. 354. 

(2) Traite du mouv. muse, Berlin, 1765, p. 289. 

(3) Mem. sur les part. sens, et irrit., sect. vi. no. 1, exp. 139-147. 

(4) Impetumfac. die. Hipp, p- 257. 

(5) Mem. sur les part. sens, et irrit., vol. iii. p. 82. 

(6) Ludwig, De substantia, cinered, Leipsic, 1779. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 177 

predominant as we descend the animal scale ; its relations with the 
medullary substance would be every where the same. 

We need not explain the progressive increase of the nerves from 
their centers to then peripheries(l) by supposed additions to this sub- 
stance, since the gray substance within them is demonstrated by no 
fact, and it is evident that the medullary substance can enlarge of 
itself. 

The most probable hypothesis is that which considers the gray and 
white substance as two masses in antithesis with each other, while 
the difference in their structure and chemical composition is ne- 
cessary to accomplish the functions of the nervous system.(2) 

§ 180. Notwithstanding the undoubted importance of the gray sub- 
stance, we have no right to think that is more noble than the medul- 
lary substance, or that the changes in the mind, corresponding to 
corporeal changes, take place in it, as Wenzel seems to think(3) when 
he says, " Cinerea singularum cerebri partium substantia videtur prceci- 
pue id esse, quo propria cuivis istarum partium sensationes ejfjiciun- 
tur ;" and tha tthe medullary substance is merely a simple conductor. 
Reil comes nearer the truth in stating that the principal organs of 
the soul are placed around the masses of gray substance within the 
the brain. (4) Haller had already advanced this theory before him. (5) 
He says, " JVon ergo in cerebri cortice sensus sedes erit aut plena causa 
muscularis motus origo ; eritque utraque in medulla cerebri et cerebelli." 

This opinion is favored by the excess of gray substance in the fetus 
and the inferior animals. 

§ 181. What is the mutual relation of .the different parts of the 
nervous systeml Do they form so many separate systems merely 
connected with each other? Or do they all emanate from a central 
part ? The last opinion has prevailed even in modern times. But 
the first begins to be general, although with several modifications. 

It supposes either two opposite nervous systems, or many which 
co-exist and are independent. 

§ 182. The first hypothesis which is defended by the most inge- 
nious anatomists(6) and physiologists, opposes to the system formed 
by the brain, spinal marrow, and theirnerves, that of the great sym- 

(1) Sprengel, Inst, phys., vol. ii. p. 191. 

(2) A hydrogen and oxygen antithesis, a gray and a white substance, appear 
to be essential parts of every nervous tissue. (Reil, Archiv fur die Physiclogie, 
vol. ix. p. 485.) 

(3) De penitiori cerebri struct., p. 69, chap. vi. 

(4) Archiv fur die phys., vol. ix. p. 207. 

(5) Elem. Phys. vol. iv. p. 392. 

(6) Winslow, Expos, anat., vol. iii. p. 220. — Johnstone, An essay on the use of the 
ganglions of the nerves, 1771. — Pfeffinger, De structurd nervorum, Strasburg, 
1783. — Scemmerring, Ucber das Organ der Seele, Konigsberg, 1796, p. 9. — We consi- 
der the last (the sympathetic nerve,) as a separate pair of nerves independent of the 
brain and spinal marrow, which is, however, connected with them mediately, but 
not immediately. — Bi«hat, Traile de la vie et de la mort., ch. vi. § iv. p. 76. — Reil, 
Archiv. fur die Physiologie, vol. vii. part ii.— Gall, Anatomie et Physiologic du sys- 
tems nerveux, 7810. 

Vol. I. 23 



178 GENERAL ANATOMY. 

pathetic or intercostal nerve which expands in the neck and in the 
cavities of the chest and abdomen, and admits only simple connections 
between these two systems, which are otherwise independent. 

As the first is distributed principally to the organs which preserve 
the relation of the mind .with external objects, and are subject to the 
influence of the will, and the second is expanded in the organs which 
are only materially connected with external objects, the first is called 
the nervous system of animal life, and the other the nervous system of 
organic, vegetative, or automatic life. 

According to this theory, the ganglions, formed of medullary fila- 
ments and of a gray substance, are so many small brains from whence 
the sympathetic nerve arises. Some of the ganglions which form 
the centres of this system are situated internally upon or beyond 
the median line of the body, and others on its edges. The nerves of 
the organs of circulation, of digestion, of the urinary secretion, and 
partly, also, those of generation, come from the first, as well as those 
filaments which unite these inner ganglions with those which are 
placed on its edge. The latter extend in a row on each side along 
the vertebral column. They connect the internal ganglions and the 
filaments which come from them with the system of animal life, since 
they unite with the cerebral and spinal nerves by one or many filaments. 

The great sympathetic nerve, on the contrary, is generally con- 
sidered either as a cerebral nerve, the trunk of which proceeds along 
both sides of the vertebral column, and unites with the spinal nerves 
by ganglions, while its branches swell out from space to space to form 
other ganglions, or as a nerve formed by all the spinal nerves. Against 
this opinion and in favor of the preceding,(l) we may adduce the 
following arguments : 

1st. What is termed the trunk of this nerve is often interrupted 
without any derangement in the organs to which it proceeds. We 
sometimes find a very distinct interval between two or more ganglions. 

2d. Other ganglions, not belonging to the sphere of the sympa- 
thetic nerves, are always distinct, and communicate by their branches 
with the cerebral nerves only. (2) 

3d. Its trunk is often divided lengthwise, which never happens 
in the other nerves. 

4th. This nervous trunk becomes evidently thicker in its passage 
downwards, so that it cannot come from the fifth and sixth pairs of 
cerebral nerves. Nor have we reason to think that it arises from any 
of the spinal nerves, since the branches which spring from the gang- 
lions are larger than those which come from the spinal nerves. 

(1) Bichat's General Anatomy, vol. i. p. 250. 

(2) Bichat also grounds his opinion on the fact, that in birds the upper cervical 
ganglion is constantly distinct, and never communicates with the lower. But 
Cuvier has demonstrated that this assertion is erroneous. Tiedemann (Zoologie, 
vol. ii. p. 45-46.) and Emmert (Reil, Archiv, p. 337.) have demonstrated thie com- 
munication still more circumstantially. We need not observe that by an impartial 
comparison of the different passages cited, we may easily judge correctly in respect 
to the claims of discovery after Cuvier. 



OF THE NERVOUS SVSTEM IN THE NORMAL STATE. 179 

5th. Its texture is different. It is softer and grayer than the other 
nerves. 

6th. Its external form does not resemble that of the nerves of the 
system of animal life, being neither constant nor symmetrical. 

These arguments prove only that the great sympathetic nerve does 
not arise from the brain or spinal marrow by a single point, and that it is 
distinguished from the nerves by several peculiarities ; but it does not 
follow that it forms a system independent of the brain and spinal 
marrow. Far from it : recent experiments would lead us to think 
that if it forms a separate system, of which the ganglions are the 
centres, while its extremities communicate with the nervous system of 
animal life, this communication is absolutely essential to the integrity 
of its functions, since the motions of the heart, which derives its nerves 
principally from it, are always arrested when the spinal marrow is 
destroyed, while only a small portion of this organ is necessary for 
their continuance.(l) 

The manner in which the ganglions placed on the borders of this 
nerve unite with the spinal nerves, also appears to favor this opinion. 
The filaments of communication arise principally from the anterior 
cords of the spinal nerves, which are immediately connected with the 
spinal marrow, instead of coming from the posterior cords, along 
which ganglionic enlargements are found. (2) 

The opinion with regard to the great sympathetic nerve, when 
thus modified, is admissible, and thus the ingenious Johnstone has 
stated it. (3) 

§ 183. Gall,(4) instead of admitting this general opposition between 
the nervous systems of organic and animal life, considers the system 
of organic life, the nerves of voluntary motion, of the senses, of the 
proper organs of the intellectual functions at least in perfect animals, 
as so many distinct and independent systems, which are closely united 
and connected in their action, but which do not come from each other. 
Trie nervous system of the senses and of voluntary motion is, how- 
ever, composed of the spinal marrow, the medulla oblongata, and the 
nerves which come from them : they may, and even should, be con- 
sidered then as one system ; since, with a few exceptions, each nerve 
is at the same time a nerve of sensation and a nerve of motion. Be- 
sides, even when we examine the nervous system of organic life, we 
do not consider the ganglions and filaments separately, nor can we 
separate the study of the nerves of perception and of motion from 
that of the brain. The preceding hypothesis is then more probable 
than that of Gall. 

§ 184. But although it is true that the animal and organic nervous 
systems differ, the second being subordinate to the first, although the 
•different parts of the nervous system considered as a whole, are united 

(t) Legallois, Exp. sur le principe de la vie, Parie, 1812. 

(2) Scarpa, Annot. acad, 1. i. §xi, xii. 

(3) hoc. cit. p. 80. 

(4) Gall, p. 467. 



180 GENERAL ANATOMY. 

in many different ways, so that they are always in a state of reac- 
tion and mutual dependence, we cannot deny but that each part is to 
a certain extent independent of the rest. Each part of the nervous 
system preserves itself in virtue of a peculiar activity, and reproduces 
itself constantly from the blood which flows to it. Hence when a 
nerve is divided it remains as large below as above the cut. 

We sometimes find nerves when there is no trace of a brain or spi- 
nal marrow, and the spinal marrow is often perfect, although there is 
not the least appearance of a brain.(l) Even when the development 
is perfect, we have instances where considerable injuries of the brain 
and spinal marrow do not diminish sensation or the power of motion, 
especially when they are not sudden, but slow and gradual. The 
limbs, when detached from the body, are agitated if their nerves be irri- 
tated. 

§ 185. Hence some late writers have opposed the opinion of the 
ancients, that the nerves and even the spinal marrow come from the 
brain, and it is admitted that these parts do not arise from the encepha- 
lon, but are merely connected with it. It is even pretended that the 
nervous system of organic life is formed before that of the nervous 
system of animal life. (2) 

They appear however to have gone too far on this side; for, 1st. 
The history of the development of the nervous system in the animal 
series, and in the fetuses of the superior mammalia, proves that the 
central part of the nervous system of animal life in fact exists before 
its radiations, and before the nervous system of organic life. In seve- 
ral worms we find in the place of a spinal marrow, only a simple cord 
destitute of filaments. (3) The spinal marrow is the first part which 
appears in the chicken, so that this organ in some measure appears 
to be the origin of the whole nervous system. In fact we find the 
spinal marrow without the brain,(4) but never find the brain without 
the spinal marrow, neither in animals nor in human monsters. When 
'the nerves are seen without the brain and spinal marrow, these two 
organs existed previously, or the defect is but partial. Hence why 
the whole brain may be extirpated. A small portion of the spinal 
marrow is sufficient to sustain life in that part of the trunk with 
which it communicates ; but if the whole spinal marrow be destroyed, 
the phenomena of life cease. (5) 

2d. The ordinary results, even of those experiments which are 
alledged to prove that the different parts of the nervous system are 
independent of each other, demonstrate that the nervous activity ema- 
nates, at least partially and perhaps entirely, from central parts. A 
limb, if its nerve be divided, becomes feeble and often wastes. The 
functions of all these parts cease when the continuity of their nerves 

(H Monroe, On the nervous system, p. 20, 21. 

(2) Ackermann, De system, nervcis primordiis, Heidelburg, 1813. 

(3) Cuvier, Anatomie comp. vol. ii. p. 330. 

(4) Cuvier, Anatomie comparee, vol. ii. § 339. 

(5) Malpig-hi, loc. cit. 

(6) Legallois, loc. cit. p. 32-3-4-131. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 181 

is interrupted, even when these nerves are connected with them in all 
their extent. Hence, in order that the nerve should perform its func- 
tions, it must communicate with the brain and spinal marrow — a fact 
from which we deduce at the same time a powerful argument against 
the opinion that the nerves possess gray substance in every part. 

The nerve has then the power of vegetating or of nourishing itself 
independent of the central part ; but it proceeds from this center, and 
must communicate with it, to animate the organs to which it goes. 

§ 186. What is the function(l) of the nervous system? What is 
the relation between its whole structure, and that of its parts, and this 
function ? 

The function of the nervous system is to produce the actions cor- 
responding to the activity of mind, the phenomena of sensibility or of 
intelligence. Consequently, it is the system of sensibility. Hence 

(1) See on this subject, Lobstein, Discours sur la preeminence du systeme nerveux 
dans Veconomie animate et Vimportance d'une etude approfondie de ce systeme, Stras- 
burg - , 1821. — Charles Bell, On the nerves — Memoir on the respiratory nerves. — Shaw, 
Experiments on the nervous system, in the London med. and pkys. journal, Decem- 
ber, 1822, June, 1823. — See also, Journal dephys. exp., vol. ii. p. 77 ; Archiv. gen. de 
med., August, 1823, p. 511. — Desmoulins, Recherches anatomiques et physiologiques 
sur le systeme nerveux des poissons ; in the Journ. dephys. exp. vol. ii. p. 348; Id. 
Exposition succincte du developpement et des fonctions du systeme cerebrospinal, 
in the Archiv. gen. de med., June, 1823, p. 223; Id. Exposition succincte du deve- 
loppement et des fonctions des systemes nerveux lateraux des organes des sens et de 
ceux des mouvemens dans les animaux vertebres, same journal, December, 1823, p. 
571. — Magendie, Experiences sur les fonctions des racines des nerfs qui naissent ae 
la moelle epiniere ; in the Journ. de phys. exp., vol. ii. p. 276-366. — Rolando, Exp. 
sur lesfonct. du syst. nerv., same journal, vol. iii. p. 95. — Coster, Experiences sur le 
syst. nerv., publiees en ltalie en 1819, et repetees en France en 1823 ; in the Archiv. 
gen. de med., March, 1823, p. 359. — Fodera, Recherches experim. sur le syst. nerv. ; 
in the Journ. dephys. exp., vol. iii. p. 191, and in the Journ. compl. du Diet, des sc. 
med., vol. xvi. p. 290, vol. xvii. p. 97. — Treviranus, Essai d'une determination du 
rapport des diff. org. cerebraux aux. div. manifestations de la vie intellcctuelle, same 
journal, vol. xvii. p. 13. — Id. Sur les organes cerebraux, les nerfs de la vie vegeta- 
tive et sensitive, et leurs connexions naturelles, same journal, vol. xvi. p. 113. — Id. 
Sur les differences qui existent, relativement a la forme et a la situation du cer- 
veau dans les differentes classes du regno animal, same journal, vol. xvii. p. 216, 
vol. xviii. p. 235. — Desmoulins, Mcmoire sur le defaut d' unite de composition du 
systeme nerveux, et sur la concordance de cc defaut atec I'irrcgularite des facultes 
des animaux, same journal, vol. xviii. p. 79. — Wilson Philip, On the influence of 
galvanism on digestion and respiration, tf*c, London — Humboldt, Resultats d 
exper.faites sur les actions galvaniques, et sur les effcts de la section longitudinale et 
de la ligature des nerfs, in the Archiv. gen. de med., October, 1823, p. 292. — 
Breschet, M. Edwards, and Vavasseur, De I' influence du syst. nerv. sur la digestion 
stomacale, same journal, August, 1823, p. 179. The last three memoirs establish 
the identity between the effects of galvanism and certain phenomena dependent 
on the action of the nervous system. Wilson Philip was the first who attempted 
to re-establish the action of the stomach suspended by the division of the parvagum 
nerve, by passing a continual current of galvanism across this organ, which was 
transmitted by the lower extremity of the divided nerve. Charles Bell's observa- 
tions on the simple and compound nerves, and those of Magendie on the different 
functions of the two roots of the spinal nerves, are, with those of W. Philip, the 
most important additions to the science of Physiology, since the commencement of 
this century. We must, however, admit that C. Bell's theory was indicated, and 
even developed, to a certain extent, in the different works of Lamarck; among 
others, in his Philosophic zoologique. — See also Vavasseur, De V influence du sys- 
teme nerveux sur la digestion stomacale, Paris, 1823. — Foville and Pinel Grand- 
charnp, Recherches sur le siege special des differentes fonctions du systeme nerveux, 
Paris, 1823. — Flourens, Recherches experimentales sur les fonctions et les proprieties 
du systeme nerveux dans les animaux vertebres, Paris, 1824. F. T. 



182 GENERAL ANATOMV. 

why a perfectly normal state of this system is indispensable to produce 
these phenomena normally. 

But its different parts have different functions. The function of the 
nerves is to convey the impressions to their opposite extremities, and 
thus produce changes in those organs which receive these impressions. 
These changes depend on the nature of the organs. They are sen- 
sations in the central part, and changes of volume or motions, and modi- 
fications of the form in the organs different from the nervous system. 

§ 187. The nerves are conductors. This is proved by the following 
facts: 

1st. The propagation of the external or internal impressions ceases, 
when their continuity or connections with the central part and the 
organs in general are interrupted. Hence the loss of motion, secretion, 
and sensation, when the nerve of an organ is cut, or compressed by a liga- 
or tumor in its course, at its origin, or at its entrance into an organ. 
Hence the loss of smell when a schirrhous tumor compresses the 
olfactory nerve ;(1) and deafness in another case, where the auditory 
nerve was compressed in the same manner ;(2) and squinting in a sub- 
ject, where the origin of the nerve of the sixth cerebral pair(3) was 
also compressed by a tumor, blindness in a case of compression of the 
optic nerve by an aneurism of the carotid artery within the skull ;(4) 
complete paralysis of the arm by the swelling of the lymphatic gang- 
lions in the axilla, thus forcibly pressing upon the brachial plexus. (5) 
Hence the derangement and even the complete suspension of diges- 
tion, and the loss of voice from tying or dividing the par vagum nerve, 
which goes to the organs of these functions. (6) 

Hence, too, excruciating pain is often cured by dividing the nerves 
of the diseased part ; and sometimes it ceases for a time, even when 
those nerves are compressed. Hence, finally, the happy use made of 
this resource against tic douleureux and similar fixed pains in other 
parts of the body. 

The number of parts, then, which lose their sensibility and motivity,is 
always much greater in proportion as the nerve is tied or divided near 
its origin. When the loss of these two powers depends on a ligature 
or on compression, they reappear when these cease to act. 

2d. The propagation of the external or internal impressions con- 
tinues to take place on one side between the point compressed and the 
central part, on the other between this same part and the organ to 
which the nerve goes. When we touch the parts of a limb above the 
place where its nerve has been cut or tied, a sensation is excited, the 
intensity of which depends on the manner in which the contact is 
made, and the degree of force given to it. Motion takes place even in 

(1} Loder, De tumore scirrhoso et organo olfactus, J6na, 1779. 

(2) Sandifort, Obs. anat.pathol. lib. i. c. ix. p. 117. 

(3) Yelloly, in the Med. chirurg. trans., vol. i. xvi. 

(4) Blane, in the Trans, of a soc.for impr. ofmed. and chir. knowl., vol. ii. p. 193. 

(5) Van-Swieten, Comm. in Bocrhaav. Aphor. vol. i. p. 222. 

(6) Leg-allois has collected all the ancient and modern references to experiments 
on this subject, (loc. cit. p. 164.) 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 183 

a limb detached from the body, when the nerve is irritated ; although 
the irritation of the parts of the nerve above this division, of the brain, 
or the changes which supervene in the encephalon, have no effect on 
the motion of a limb, the nerve of which is only tied. 

3d. Other things being equal, the degree of sensibility and of moti- 
vity of an organ depends on the size of its nerves. Hence the large 
size of the nerves of the organs of the senses, which probably contri- 
butes to render them more susceptible of being affected by certain qua- 
lities of bodies, although the structure of the organs to which they 
go, their mode of distribution, and the differences in the internal struc- 
ture of the nerves themselves, are the principal sources of this faculty. 
Hence why those muscles of the eye which move continually receive 
the most and largest nerves. The nerves of the heart are neither so 
large nor so numerous as those of the other muscles, but they come 
from ganglions which communicate directly with the spinal marrow, 
and they have more medullary substance in proportion to the neuri- 
lemma, than the other nerves. 

4th. The central part of the nervous system experiences no change 
from internal impressions made on the organs which do not receive 
nerves. These organs are insensible (p. 79). 

§ 188. The external and internal impressions are generally con- 
ducted always in the same direction. It rarely or never happens that 
when we touch a nerve, we produce motions in those muscles, which are 
supplied with nervous filaments from the trunk, between the point of 
contact and the central part. Thus the nervous influence which is to 
act on the external organs goes directly to the periphery. 

§ 189. As the phenomena which result from the conducting power 
of the nerves are finally reduced to sensation and motion, the nerves 
have been "divided into nerves of motion, nerves of sensation, and mixt 
nerves. But this classification is valueless ; for although there are 
some nerves intended exclusively for sensation, (as the olfactory, optic, 
and auditory nerves,) there are none which are designed simply for 
motion. Those which go to the muscles have in fact only the power 
of propagating impressions from their periphery inward. 

§ 190. The same nerves convey external and internal impressions, 
since the section of one of these cords destroys both sensation and mo- 
tion. The divisions of these organs into nerves of sensation and nerves 
of motion, is then incorrect in this second respect. 

On the contrary, the phenomena above mentioned (§ 188) lead us 
to conjecture, with some probability, that there are in the same nerve, 
different fibres, some designed to convey impressions inward, and others 
to carry them externally : at least these phenomena are explained very 
satisfactory by this hypothesis. In fact, the fibres do not apparently 
differ in arrangement, but the variation may, however, be so slight as 
to escape us ; hence we draw no conclusions. 

This hypothesis is, besides, more probable than that which sup- 
poses that the transmission of impressions internally differs from that of 
conveying them externally, and that it requires less energy to con- 



184 CENERAL ANATOMY. 

duct external than internal impressions. The partisans of the last 
theory found it on the circumstance, that the loss of motivity is observed 
oftener than that of sensibility. Still the contrary case is not rare ; 
some physiologists believe, even, that it requires more energy to propa- 
gate external impressions. And again, the sensibility almost entirely 
disappears in raphania, although motivity is but slightly diminished. 

Finally, the loss of one of the two faculties, with the continuance of 
the other, demonstrates neither the existence of nervous fibres differ- 
ing in their conducting power, nor the necessity of greater energy to 
propagate either internal or external impressions, since the cause of 
the loss of sensation and motion unquestionably depends on the abnor- 
mal state, not of the conducting nerve, but of the centre to which it 
extends, or of the organ in which its periphery is expanded. 

Still less can we admit, that the conducting power of external and 
internal impressions resides in different substances, viz. that of internal 
impressions in the medullary substance, and of the former in the neu- 
rilemma. All the arguments adduced in support of this improbable 
hypothesis are easily refuted. (1) 

Considering all things, it is probable, 1st, that the conducting power 
resides in the medullary substance alone, and not in the neurilemma. 

2d. That all the fasciculi and all the fibres of the nerves equally 
fulfill the function of transmitting the external and internal impressions, 
even as the same muscular fibres contract sometimes in one direction, 
and sometimes in the opposite. 

§ 191. The following facts demonstrate that the nerves possess only 
the conducting power ; that is, they are only the necessary means 
of producing intellectual phenomena, in accordance with the im- 
pressions transmitted by them to the centre of the nervous system, 
and that, in man at least, the brain is the only organ in which changes 
corresponding with the phenomena of intelligence occur. 

1st. The only portion of the nerves which is not sensitive, and 
which loses the power of exciting voluntary motion, is that which is 
separated from the rest of the nervous system by compression or 
division. 

2d. The intellectual acts remain entire when the communication 
between the brain and the rest of the nervous system is interrupted, 
and there is paralysis of all those parts of the body which are situated 
below the parts injured, as, for instance, in dislocations, or fractures of 
the cervical vertebrae accompanied by compression of the spinal mar- 
row. (2) 

(1) Treviranus, On the nervous influence audits effects, in Phys. Fragmcnta vol 
i. Hanover, 1797, vol. ii. 1799. . 

(2) Vicq d' Azyr has seen the paralysis of the extremities and of the sphincters of the 
anus and bladder, with an insensibility of the whole body, except the head from an 
injury of the cervical portion of the spinal marrow. (Encyc. method. Med. Anat. 
pathol, p. 264.) Ludwig- has known loss of motion and sensation in the whole body 
after a fracture of the fourth and fifth cervical vertebra; ; the patient continued per- 
fectly sensible for sixteen days. (Advers. med. prop. vol. iii, p. 507.) 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 185 

3d. The intellectual functions are more or less injured by the compres- 
sion, irritation, destruction,violent concussion of the brain, and bychanges 
in its physical qualities ; by the too great or too little flow of blood to 
this organ ; in a word, by all anomalies which can exist in it, although 
the structure of the other parts of the nervous system is perfectly normal. 

4th. These lesions disappear when the cause which acts on the brain 
is removed or when the action of this organ returns to its normal rythm. 

5th. The development of the intellectual faculties is parallel with 
that of the brain, in regard to its mass, form, chemical composition, 
and distinction of its two substances, both in the fetus and in animals. 
But we should not forget that the increase of the encephalon in size 
is not exactly ascertained by comparing the brain and nerves together. 
The large animals have, 1st, a brain positively larger than the small ani- 
mals, and sometimes larger than that of man : 2dly, in many, also, it is 
larger, in proportion to the body, than in others, without a correspond- 
ing development of intellect. On the contrary, there is constantly a 
direct relation between the development of intelligence and the increase 
of the brain, when compared to that of the nerves. This relation is no 
where more favorable than in man. 

6th. Even from the sense of effort and fatigue in thinking, which 
very evidently has its seat in the head,at least in preference to other parts. 

7th. The brain, although united to the rest of the nervous system, 
forms a separate and perfectly distinct organ, which fulfills special 
functions. 

8th. After a painful limb has been amputated, the patient thinks he 
still feels pains at the stump. 

§ 192. Most of these facts, especially the 2d, 3d, 4th, 5th, 6th, and 
7th, prove at the same time that, at least in man and the superior ani- 
mals, the brain is the only central part of the nervous system which co- 
operates with the phenomena of intelligence, and that the spinal mar- 
row takes no direct part in them. 

§ 193. Does the whole brain take part in all acts' of intelligence, or 
do certain intellectual phenomena occur in some particular parts 1 In 
one or the other case, is there, or not, some more or less extensive part 
of the encephalon where the primitive source of all spiritual or corporeal 
life resides, in this respect, that the local or general changes which take 
place in the brain are reflected in it, and that it is the point of de- 
parture of all cerebral influence to the nerves ? 

Observation and experiment can alone assist in resolving these ques- 
tions. 

The arguments in favor of the first opinion, are, 1st, that most of the 
brain may be destroyed without a sensible diminution of the intellectual 
faculties ; 2d, that the destruction of the same part of the brain does 
not always necessarily involve that of the same intellectual faculty ; 
3d, that the complication of the brain remains the same, while its mass 
and volume increase in proportion to the development of intelligence. 

We may conclude from this, that the whole cerebral mass acts in all 
intellectual operations, and that a part of this organ, by increasing its 
activity, can well replace those which may be destroyed. 

Vol. I. 24 






166 GENERAL ANATOMY. 

The following are the facts in favor of the second hypothesis : 

1st. The difference of the intellectual operations, and of the moral 
qualities which appear to correspond to the complicated and constant 
structure of the brain. 

2d. The development of certain parts of the brain corresponding with 
that of certain intellectual faculties, and reciprocally. 

The arguments favorable to the first hypothesis may be adduced 
against the second. But we must remark, 

1st. That it is very difficult for two injuries of one and the same part 
to be perfectly similar. 

2d. That from the symmetry and doubleness of the cerebral parts 
of the brain, the lesion of one of its two portions may be unattended 
with inconvenience. 

3d. That those parts even which do not exactly correspond may 
supply them, since we see organs formed very differently, as the skin, 
the kidneys, the lungs, the intestinal canal, the mamma?, the perito- 
neum, &c, replace each other. 

It is, then, not improbable that the different faculties of the soul have 
different organs in the brain, even as the different corporeal functions, 
ani the different acts of one and the same function, are performed in 
the body by different organs, but it is difficult to assign the seat of 
these faculties ; we can only say that those of a secondary order re- 
side in the lower and posterior parts of the brain, while the most noble 
faculties exist in the upper and anterior. In fact, 

1st. The inferior parts are found in all vertebrated animals com- 
mencing with the lowest in the scale. 

2d. They do not differ much in different animals. 

3d. As the intellectual faculties perfect themselves in the animal se- 
ries, and in different individuals of the same species, the cerebral mass 
increases upward, forward, and on the sides ; the hemispheres enlarge 
in respect to the inferior parts of the brain, which have a definite out- 
ward form, and appear as distinct organs ; and the cerebrum is larger 
in proportion to the cerebellum. 

§ 194. The nervous system is not only the organ of the mind ; it 
animates also all the other organs, because it probably exists before 
them, and because the vital energy of these organs is proportional to the 
size and number of the nerves they receive, and the destruction of their 
nerves deranges more or less the fulfillment of all their functions. Is 
there a common source of this vivifying and preservative power of the 
nervous system, or is it diffused through the whole of it % 

That the periphery of the nervous system takes no part in the pre- 
servative influence exerted upon the whole organism, is proved by the 
fact that all the limbs may be amputated without destroying life. The 
source of this faculty undoubtedly resides in the central part. But 
is it diffused through all the central mass, or confined to a particular 
part 1 The former is not true ; of this we may be convinced by com- 
paring the degree of tenacity of life in those animals in which the brain 
is considerable, and those in which it is small. The difference in this 
respect must undoubtedly be ascribed to this, that the two conditions 



OP THE NERVOUS SYSTEM IN THE NORMAL 8TATE. 187 

are directly opposed to each other. Experiments seem to demonstrate 
that the source of the preservative power, which exerts an influence on 
the whole organism, resides in the medulla oblongata ; since if this 
part be injured, life is destroyed sooner than from wounds of any other 
part of the brain or spinal marrow ; and farther, the latter have been 
found changed, and the vital functions have not been affected. This 
part is principally important because the par vagum nerve arises here 
and goes to the organs of respiration ; for when that is injured, the se- 
cond condition, which is essential to maintain life, the change of 
venous into arterial blood in the lungs, no longer takes place, and the 
vital energies cannot be produced. Thus, after destroying the medulla 
oblongata, and even separating the head from the body, if artificial respi- 
ration is carried on, the trunk continues to live during a certain period, 
if the spinal marrow be uninjured, and the vessels are carefully tied to 
prevent the loss of arterial blood ; but if the spinal marrow be destroj'ed, 
all the vital phenomena cease, although respiration is continued. 
If a portion of it only be destroyed, life ceases only in those organs 
which receive their nerves from this part. The medulla oblongata is 
then not so important to all the organism, except as a medium. The 
true source of the preservative power of the nervous system resides in 
the posterior and inferior part of the encephalon and in the spinal marrow, 
and the integrity of all these parts is absolutely necessary to maintain 
life. This is farther proved by the fact, that although when part of the 
spinal marrow is destroyed, the vital phenomena cease instantaneously 
only in those organs to which it sends nerves, yet the other organs also 
soon perish, and at the same time as when the heart is removed and 
the spinal marrow uninjured. The destruction of the nervous system 
appears then to cause death by checking the circulation of the blood. 
Hence why the motions of the heart become much weaker when a part 
of the spinal marrow is destroyed ; and the reason too that when a 
considerable part of this cord is destroyed, life remains so much longer 
if the circulation be carefully restricted to a few organs, and the 
relation between the extent of the circulation and the force which re- 
mains in the heart after the lesion of the spinal marrow, be more 
favorable. 

§ 195. The nervous system is also the medium between all the 
organs. It unites them all, and changes in one are felt not only in the 
central mass, but also produce changes in the other parts of the body. 
It is then the organ of sympathies. 

§ 196. The texture of the nervous system and the numberless com- 
munications of its different parts, greatly favor the development of sym- 
pathies. The plexuses of the nerves seem to be the medium of these 
sympathies, since they unite the filaments of the different nerves ; so 
that the branches given off by them, are always composed of filaments 
from two or more of these different nerves. 

The nervous filaments separate and unite in the ganglions also. 
Hence they have been regarded in the same light as the plexuses, and 
their uses have been considered — 



188 GENERAL ANATOMY. 

1st. To increase the ramifications of the nerves, and to render them 
more minute, since on entering them, the nerves abandon their neu- 
rilemma, and are reduced to their constituent filaments, which receive 
a thinner and softer envelop when they emerge. 

2d. To facilitate the passage of the branches of the same nerve to 
different organs, and to guard them against the dangers which might 
attend them in a long course. 

3d. To unite in a single trunk several filaments of one, or of different 
nerves, or the different roots of the same nerve.(l) 

But, then, we cannot conceive why the ganglions differ so much 
from the plexuses, or even why they exist ; it seems, then, more natural 
to think, that these organs increase in some manner the action of 
the nerves, an opinion which many ancient and modern physiologists 
have sustained with different modifications. 

§ 197. The ancient anatomists were more strenuous to prove the 
existence of these ganglions than to determine their uses ; still, Galen's 
opinion seems to have been, that they increased the action of the 
nerves. He says, " Ubi enim aut longo itinere nervum est (naiura) due- 
turum, exiguum aut motui musculi vehementi ministraturum, ibi substan- 
tiam ejus corpore crassiori quidem, c&tera autem simili, intercipit."(2) 
Willis,(3) and Vieussens,(4) that they prepared, perfected, or modified in 
some manner the active principle of the nerves. We may consider as mo- 
difications of this theory the opinion of Lancisi,(5) that they possessed 
muscular fibres to quicken the course of the active principle of the nerves, 
to render this principle more prompt in obeying the impulse of the will, 
and that of Gorter,(6) who believed them designed to concentrate the 
blood vessels,which, by their action,favor the passage of the nervous fluid. 
Lancisi, Winslow, Lecat, Winterl, Johnstone, Pfeffinger, Monro, Bichat, 
Gall, and Reil, have considered them as small brains, secondary brains, 
sources to increase the nervous power, because they are, like the brain, 
composed of a white and a gray substance, and because the latter 
is as vascular as in the encephalon; and farther, in the fetuses des- 
titute of a brain by primitive formation, or where the brain has been ac- 
cidentally compressed, the substance which replaces it very much re- 
sembles, in color and consistence, the nervous ganglions ; and finally, 
because the nerves given off by the ganglions are larger and more nu- 
merous than those they receive. Even the analogy between the struc- 
ture of the nervous ganglions, and that of the lymphatic glands has 

(1) Meckel, Obs. anat. sur un nceud ou ganglion du second rameau de la cinquieme 
paire des nerfs du cerveau, nouvellement decouvert, avec Vexamen pkysiologique du 
veritable usage des ganglions des nerfs, in Mem. de I' Ac. de Berlin, 1749, p. 85-102. 
Zinn, ibid. p. 753 ; De Venveloppe des nerfs, p. 144.— Scarpa, Ann. Acad. Mutirue, 
1799, B. i.— Haase, De gangl. struct, p. 32-35. 

(2) De usu part. corp. hum. B. xvi. c. v. The nervous ganglions were discovered 
by Galen. F.T. 

(3) Descript. nerv., in Opp. omn., Geneva, 1695, p. 120. 

(4) Neurogr. p. 193. 

(5) Diss, de structura usuque gangliorum annex. Morgagni advers. an. V. 

(6) Chirurgia repurgata, Leyden, 1742, p. 184. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 189 

been adduced in support of this hypothesis, because it has been con- 
cluded that their functions ought also to be analogous. 

This opinion is far from being contradicted by asserting, that the ex- 
istence of the animal spirits is not demonstrated, which, according to the 
ancient physiologists, were produced, elaborated, kept in reserve, and 
rapidly propelled by the ganglions,(l) or that the structure of the or- 
gans which secrete them ought to be much more delicate, and that the 
mass of nervous substance does not increase in the ganglions, but that 
in them the filaments of the nerves are only divided into smaller fila- 
ments ;(2) and finally, that the structure of these ganglions is not simi- 
lar to that of the brain.(3) The imponderable principle which acts in 
the nerves is not what the ancients termed vital or animal spirits, and 
although we are now better acquainted with its laws, although we sus- 
pect it extends throughout all nature, this knowledge does not affect 
the state of the question in the least. We know of no other organ 
which can secrete it, except the gray and white substance, and both of 
these exist in the ganglions. But the ganglions are similar even in 
this respect to the brains, and although the anatomy of the superior ani- 
mals does not prove this identity, we cannot doubt it, when we compare 
the ganglions and the brain of the inferior animals ; in fact, it often hap- 
pens in these animals, that the different ganglions have the same inner 
and outer structure, and the same volume, as the brain. 

We may, then, consider this opinion as demonstrated generally, al- 
though its. different modifications are somewhat erroneous. Thus, for 
instance, Lancisi's assertion is untrue, that the function of the gang- 
lions is to determine the flow of the vital spirits into the voluntary mus- 
cles ; for the organs which receive their nerves from these enlarge- 
ments are in fact the involuntary, such as the heart, viscera, &c, al- 
though he maintains the contrary. It is, then, much more correct to 
say with Johnstone, that the ganglions interrupt the influence of the ce- 
rebral action on the organs, and to admit, with Haller and Metzger, that 
they blunt the sensations, in short, that the organs to which they send 
their nerves are more insulated than the others from the rest of the 
nervous system. In fact, the nerves of several of the voluntary mus- 
cles also have ganglions ; but they are formed from their posterior 
roots alone, and these do not unite to the anterior, till after the gang- 
lions are produced. Finally, from what has been stated above(§ 182), 
it is wrong to say that the ganglions are situated in the course of the 
nerves to interrupt the cerebral influence ; the nerves emerge from 
the ganglions and are connected with the rest of the nervous system 
only by intermediate filaments ; the ganglions are centres, and hence 
the organs which they animate are insulated. 

It follows, then, that several functions which have been considered 
as so many principal functions of the ganglions, are merely subordinate 

(1) Scemmerring, Nervenlehre, p. 130. 

(2) Haase, loc. cit. p. 19, 20. 

(3) Haase, loc. cit. p. 25. 



190 GENERAL ANATOMY. 

and inferior, or rest only on false suppositions. Thus, according to 
Zinn, the ganglions are designed to give a cellular envelop to the 
nerves which come from them. But the relation of the cellular tunic 
of the nerves with the ganglions, does not differ from that of the neuri- 
lemma with the pia mater of the brain or spinal marrow. It appears 
wherever a nerve is formed. Nor is the use of the ganglions to unite 
the different filaments of the nerves in a single trunk, as Meckel has 
pretended. This anatomist rested his opinion principally on the fact of 
the ganglions of the spinal marrow ; but Haase has demonstrated (he 
incorrectness of the pretended fact. It is true that the nervous fila- 
ments ramify and interlace in a thousand ways in the compound gang- 
lions ; but the same is the case in the brain and spinal marrow. We 
then have more reason to say, that the ganglions establish a contrast 
between the nerves which they give off and those which they receive; 
since the former are reddish and soft, and they are easily distinguished 
by their color and degree of solidity from those with which they anas- 
tomose. 

§ 198. The nervous system differs considerably during life, both in 
itself and in its relations with other organs.(l) 

The following are the most remarkable peculiarities in this respect : 
We have already observed (p. 45) that the nervous system is one 
of the first, if not the very first, which appears. Are all its parts seen 
at once, or successively ? If they arise in succession, in what order do 
they appear ? This is, perhaps, no place to decide whether the nerves 
appear in those regions of the body which are formed after the others, 
later than in those parts which show themselves the first ; if, conse- 
quently, they develop themselves first or last in the extremities. The 
problem reduces itself to determine if the central and peripheral parts 
do or do not arise at the same time, and if the latter be true, which ap- 
pears first. As the nervous and vascular systems, and the intesti- 
nal canal, are formed entirely or almost entirely together, the smallness 
of the ' objects renders it almost impossible to determine if the parts 
which are first seen, be the central parts of the 'nervous system, or if 
they belong to the vessels, or to the intestines. Analogy favors the 
first hypothesis ; for in many worms we find only a single cord extend- 
ing the whole length of the body, which does not give off any nerves; (2) 
and also different organs, particularly the heart, the intestinal canal in 
the animal series, and even the whole body of the fetus, form in this 
manner, that is, we see the trunk first, and then the branches which 
proceed from it. 

(1) J. and C. Wenzel, loc. cit. chap. 27, 28, 29, 31, 34.— Dasllingerrs, Beitrcege zur 
Entwicklungsgeschichte dcs menschlichen Gehirns, Fvant, 1814. — Ackerman,£>esys- 
tematis nerveiprimordiis, Heidelberg, 1813.— Carus, loc. cit. p. 262-265 and 277-297. 
Meckel, in the Deutches Archiv Jiirdie Physiologie, 1815, vol. i. chap. 1 and 3. 

(2) Cuvier, Anatomie compared, vol. ii. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 191 

But which of the central parts appears first % There are two cen- 
tral masses, formed one by the encephalon and the spinal marrow, the 
other by the ganglions of the grand sympathetic nerve (p. 177). Does 
the former appear before the latter ; and are certain parts of these two 
masses formed before the others 1 

The most probable opinion is that which attributes priority of origin 
to the encephalon and spinal marrow. This is supported, 

1. By observations on the fetus ;(1) and, 

2. By the analogy of the development of the nervous system in the 
animal series ; for that part of the system found in imperfect animals 
corresponds to this portion. 

The same reasons should apparently lead us to think that the spinal 
marrow is formed before the brain. We may add to these the fol- 
lowing : 

a. The size of the brain in proportion to that of the spinal marrow 
always diminishes as we descend the animal scale, b. The spinal 
marrow is perfected long before the brain, c. We sometimes see 
deformed fetuses in which the upper part of the body, and consequently 
the brain, is deficient, but never those in which the brain and upper 
part of the body are alone formed. 

Other arguments have also been adduced to favor the priority of the 
spinal marrow. ' Some have thought to demonstrate that it was indis- 
pensable, by saying that " the central organ of sensitive life ought 
necessary to develop itself at the same time with the heart, the central 
organ of vegetative life. "(2) But, as the spinal marrow appears before 
the heart, as in the fetus ; and, as in some animals, (insects,) we find 
nerves and even a spinal marrow, but no real heart ; and, as in the 
invertebral animals, the position of the heart is not constant, although 
that of the central part of the nervous system never varies, this 
explanation, imagined to establish that the spinal marrow necessarily 
precedes the brain, is as little plausible as most explanations of the 
same kind. 

Ackermann has advanced another opinion, to which it may be 
objected that it does not rest on observation. He thinks that 
the sympathetic nerve is formed first, and that its priority is 
equally necessary, because the heart, the organ possessing the 
highest degree of vital energy, is the centre of vegetative life. 
According to Ackermann, in fact, the globules of the blood pass 
through the substance of the heart, and arrange themselves in a series, 
to produce the fibres of the nerves, the softness and transparency of 
which he considers as another proof of this priority. He admits that 
the nervous system reaches the skull along the large vessels which 
arise from the heart, and that its mass gradually increases, to form the 
encephalon and spinal marrow ; that the latter is formed by the brain, 
and is a prolongation of the cerebrum and cerebellum. Against this 

(1) Malpighi, De ovo incubato, Op. ana/.., London, 1686, p. 4. Post diem inte- 
grum — tres ampliores vesiculce, cumproductd spinali medulla ; and in the Appendix : 
Elabcnte die — spinali medullce — cui vesiculce cerebri appcndebantur. 

(2) Carus, loc. cit., p. 78. 



192 GENERAL ANATOMY. 

hypothesis may be adduced most of the objections to that of the nervous 
system necessarily appearing at the same time as the heart, to contrast 
with it, and also the arguments which demonstrate the priority of the 
spinal marrow. (1) In truth, Ackermann admits this priority of the 
spinal marrow, which he construes favorably to his hypothesis, saying 
that the nervous system of the invertebral animals corresponds to the 
great sympathetic nerve of the superior animals, but not to their ence- 
phalon nor to their spinal marrow ; but this comparison is not cor- 
rect.^) In fact, the arrangement of these systems in the invertebral 
animals proves that it may be compared to the cerebro-spinal system, 
since, 1st, .the nerves come from its centre, and they are seen to arise 
from the same place in the superior animals ; 2d, some parts of this 
nervous system are developed in the upper classes of the invertebral 
animals, as the cephalopodous mollusca, so as to resemble the brain ; 
finally, in these same animals we see a second nervous system, which 
corresponds to the sympathetic nerve, and which communicates with 
the other, in the same manner as in the superior animals. Let us also 
add, that if Ackermann's hypothesis be correct, there should be a 
period of life when the sympathetic nerve is much greater than the 
brain and spinal marrow, or at least should be largely developed in 
proportion to them ; but this is not the case. Besides, the experiments 
of Le Gallois have proved that the life of the sympathetic nerve and 
of the organs animated by it depends on the spinal marrow,(3) which 
could not be true if this nerve were formed before all the other parts of 
the brain, and if the spinal marrow were only an expansion from it. 

According to Ackermann's hypothesis, the spinal marrow is not 
formed before the brain. This physiologist thought to reverse the 
argument drawn from acephalous monsters, by saying that in this 
monstrosity the brain is never primitively deficient, but that it has been 
destroyed by disease ; but this etiology of acephalia is admissible only 
when it is applied to monsters which have the body perfectly de- 
veloped, but not the skull. There, in fact, every circumstance induces 
us to think that the brain, developed more or less irregularly according 
to the primitive type of the fetus, has been destroyed by an accumula- 
tion of serum. But we must distinguish these cases from the true 
acephalia, where most of the upper half of the body is deficient, and 
there is no trace of its having been destroyed. Besides, even when 
this argument in favor of the priority of the spinal marrow is refuted, 
all the others retain their weight. 

§ 199. It is then almost demonstrated, that the spinal marroxo is 
that part of the nervous system which is first seen. But the brain soon 
appears at its upper extremity. This conjecture seems very probable 

(1) Carus (loc. c#.,p. 79) has made g-ood use of these reasons; but, unlesa we are 
much mistaken, he has collected them ag-ainst himself. 

(2) At least Ackermann's reason is fncorrect, that the sympathetic nerve, as an 
inferior nervous system, must develop itself in the class of animals lower than where 
the more exalted brain and spinal marrow are found. 

(3) Le Gallois, Exp. sur le principe de la vie, Paris, 1812, p. 151. 



OF THE NERVOUS SYSTEM IN THE NORMAL STATE. 193 

from the progressive development of this organ in the fetus and in the 
animal series, since those parts which are situated the farthest forward, 
and are consequently the most distant from the primitive source of the 
spinal marrow, are developed the slowest, that is, they appear and 
enlarge the last. So too the great sympathetic nerve develops itself 
in front of the spinal marrow, in the form of a series of ganglions, which 
communicate with it and with each other by medullary cords. The 
brain and sympathetic nerve retain the distinctive characters of se- 
condary formations longer than the spinal marrow. They preserve 
them even through life, since the different masses of ganglions which 
form them do not unite in one, but represent a series of organs more or 
less similar, as in the nervous system of the invertebral animals. On 
the contrary, the spinal marrow forms a single mass, in which we 
distinguish only two lateral parts, and which, examined from one 
extremity to the other, no where resembles a series of ganglions. The 
great sympathetic nerve, which is only an imperfect repetition of this 
organ, appears later even than the brain, if we may judge from its 
imperfect appearance ; for its component masses are still more distinct 
and separate than those of the encephalon. 

§ 200. The nervous system, proportionally speaking, is much larger, 
softer, and moister in the early than in the subsequent periods of life. 
The reason that the proportion of the liquids exceeds that of the solids 
is that the parietes of the permanent cavities are much thinner when 
the organism is younger, and because some of its cavities, as that of the 
spinal marrow, are soon obliterated. 

The texture of the nervous system differs remarkably at different 
periods of life in this respect, that at first there is no distinction between 
the gray and the white substance, and that all the nervous mass has 
at first a grayer tint. 

It whitens in the nerves and in the spinal marrow sooner than in the 
encephalon, within which the medullary substance is darker than the 
gray substance, even sometimes after birth : this arises from its great 
number of vessels. 

The lower parts of the brain assume their medullary appearance 
before the upper portions. 

The nervous system differs also in other respects at different periods 
of fife. At first, its surface is perfectly smooth, and its proportional 
size and the forms of its different parts do not remain the same. Thus, 
at first the spinal marrow fills the whole length of the vertebral canal, 
the cerebellum is smaller than the tubercula quadrigemina, and these 
are as large as the cerebrum. 

§201. As the sexual differences, we shall mention that the vo- 
lume of the brain is larger in proportion to the nerves and the rest of 
the body in females, than in males ; and for the differences of races, 
that the nerves are proportionally larger in the negro. 



Vol. I. 25 



194 GENERAL ANATOMY. 

ARTICLE SECOND . 

OF THE NERVOUS SYSTEM IN THE ABNORMAL STATE. 

§ 202. We shall commence the history of the anomalies of the ner- 
vous system by that of the accidental injuries with which its form may 
be affected, as this will naturally lead us to speak of its power of re- 
generation. 

The changes in the structure of the nerves, caused by the wounds 
of these organs, differ much from those seen in other parts of the body 
in similar circumstances. 

When a nerve is divided, its extremities always swell into a forger 
or smaller tubercle.(l) The color of this tubercle is grayish, and it is 
often so hard and solid that the scalpel glides off when cutting it, 
and the sound resembles that from cutting cartilage. The size of this 
tubercle is in direct ratio with the abundance of cellular tissue, and to 
the time which has elapsed since the wound. It not only enlarges in 
time, but also becomes harder. 

The tubercle of the upper extremity is smaller, but as hard as that 
of the lower. That portion of the nerve below the section, withers and 
loses its distinctive color. 

In amputations, this tubercle seems not to develop itself exactly at 
the extremity of the divided nerve ; at least, Van Horn(2) has found 
that an inch above the wound, the nerves were blended with the granu- 
lations of the muscles, and could not be distinguished from the mass. 
One month after the operation, they were reddish internally and exter- 
nally, and the tubercle distinguished from the end of the nerve by its 
whiteness, was then situated still higher. The lower end of the nerve 
is wasted more or less, like that of all other organs. Finally, the tu- 
bercles are seen both in the small and the large branches of the nerves, 
and they remain apparently during life. 

§ 203. If the lower part of the nerve has not been removed, it unites 
with the upper portion. But observers are not agreed on the nature 
of the uniting substance. Some think it real nervous substance, 
while others consider it simply as a cellular tissue, or coagulated 
lymph, which can never acquire the peculiar structure of the nerves. 
Hence the dispute in regard to the regeneration of these organs. 

There are two ways of ascertaining if an organ be renewed ; these 
are, to study its functions, and to investigate the nature of the substance 
formed in place of the portion removed. The first method is very un- 
certain, since the mechanical arrangement of the nervous system is 
such, that the nerve which is divided may be replaced by the anasto- 
mosing filaments, and a substance imperfectly analogous to that which 

(1) Amemann, Ueber die Reproduction der Nerven, Gottingen, 1786,"p.'48.— Id. 
Versuche ubcr die Regeneration der Nerven, Gottingen, 1787. 

(2) De iis quos in partibus membri, prcesertim osseis, amputatione vulneratis notan- 
da sunt, Leyden, 1803, p. 33-35. 



OF THE NERVOUS 8YSTEM IN THE ABNORMAL STATE. 195 

normally exists, is sufficient to unite the two extremities so perfectly, 
that the functions may be performed with perfect regularity. The se- 
cond method is more certain, but is also liable to deceive. 

Cruikshank,(l) Haighton,(2) Fontana,(3) Monro, Michaelis,(4) and 
Mayer,(5) reasoning from different researches, have admitted that the 
nerves have the power of perfect regeneration. Arnemann, on the 
contrary, thinks himself authorized, by numerous observations, to deny 
it. He states(6) that the extremities of the nerves are always united 
by cellular tissue, condensed by inflammation, which sometimes ac- 
quires the hardness of cartilage, and fills up the space more or less 
perfectly, accordingly as the nerve was more or less surrounded with 
cellular tissue, and that it gradually and slowly becomes consolidated 
with the two extremities of the nerve. Munro(7) has also found that 
the newly formed substance has always a deeper color. 

Fontana believed that true nervous substance was reproduced in 
some cases where he had removed from the intercostal nerve, a portion 
six lines in length, because that the nervous filaments passed uninter- 
ruptedly through this substance, in going from one end of the nerve to 
the other. 

Michaelis removed portions of nerves, nine or ten lines long, and 
found, after eight weeks, that the extremities of these nerves were 
united, by a substance perfectly similar or nearly so, to the nervous 
substance. The transition from the old to the new nerve was but 
slightly perceptible by the microscope. 

Mayer, having removed portions one or two lines long, found the 
extremities of the nerves reunited by filaments more or less fine, which, 
like the true nervous substance, did not dissolve in nitric acid ; but, on 
the contrary, became harder, and consequently possessed one of the 
most essential qualities of this substance. 

Haighton divided in a dog the pneumogastric nerve on one side, and six 
weeks after, that of the opposite side ; in six months the animal had entire- 
ly recovered. But all dogs in which the two par vagum nerves 
were cut simultaneously or shortly after each other, died. Hence he 
concluded, that death did not occur in the first case, because the wound 
of the nerve was cicatrized perfectly in six weeks. Still the function 
might have been performed by the other nerves, which, perhaps, had 
enlarged. If this was the case, the animal would continue to live when 
the two pneumogastric nerves were divided simultaneously. Haigh- 
ton repeated this experiment, but the animal died : proving that the 
functions were re-established, because the substance of the nerves was 
reproduced. 

(1) Experiments on the nerves, fyc. in Reil, Archiv. vol. ii. p. 57-81. 

(2) Experiments on the reproduction of the nerves, ibid. p. 79. 

(3) Versuche iiber das Viperngift, part ii. 

(4) Ueber die Regeneration der Nerven, Cassel, 1785. 

(5) Reil, Archiv fur die Physiol, vol. ii. p. 449. 

(6) hoc. cit. p. 47. 

(7) Ueber das Nervensystem, p. 94. 



196 GENERAL ANATOMT. 

Arnemann has rejected all those experiments in favor of the repro- 
duction of the nerves, in which they were merely divided and no 
portion of them was removed, saying, that in these cases there 
was no reproduction. But the difference in the cicatrization of 
wounds, with or without loss of substance, is only in degree ; since the 
simple wounds do not unite immediately, and the lymph which trans- 
udes gives rise to a new substance which joins their two extremities. 
The above mentioned experiments seem to authorize the belief, that 
the new substance, which is homogeneous in the wounds of all organs, 
may gradually become real nervous tissue. Farther, we cannot con- 
clude that this new substance is not nervous, because its characters differ 
from the old nervous substance ; for the bones, when newly formed, 
also vary in form and structure from those which are old* 

Wounds of the encephalon, when attended with loss of substance, 
also cicatrize by a new substance there developed, which is unlike the 
normal substance of the organ. It is more yellowish, and more easily 
distinguished from the gray and the medullary substance. The yellow 
substance of the brain resembles it the most. Its tissue is loose and soft, 
and sometimes entirely mucilaginous. However, the circumvolutions 
of the brain are sometimes formed from it. It generally closes the 
wound entirely, its edges approaching the centre. Another circum- 
stance very favorable to the cicatrization of wounds of the brain, is the 
enlargement of the ventricle on the diseased side, while neither life nor 
health are affected. We sometimes find a viscous or coriaceous mat- 
ter within the new cerebral substance, which Arnemann thinks is 
formed hy the coagulable lymph, thrown out from the wound of the 
temporal muscle. It is firmer and redder than the new cerebral sub- 
stance, and is usually filled with new vessels.(l) 

§ 204. The principal anomalies in the form of the nervous system 
are : 

1st. Its absence, totally or partially. A deficiency of the whole sys- 
tem is rare,(2) and is usually attended with an imperfect development 
of the whole organism, which is undoubtedly caused by it. 

A partial deficiency is more common. Usually a greater or less por- 
tion of the brain is absent, and it sometimes happens that the spinal 
marrow does not exist, or that a part of it is wanting. Sometimes 
the whole brain is deficient, while the spinal marrow is perfectly de- 
veloped. This state, attended or not with the imperfect formation of 
the adjacent parts of the body, is called acephalia, or more strictly 
anencephalia. We shall mention its principal characters when we 

* M. Flourens, in a Memoir in the Ann. des Sc. Naturelles, Feb. 1828, states that 
having repeated the experiments of Fontana, Montana, Cruikshank, and others on 
the reunion of the divided extremities of the same nerve, he sought to determine 
the effects resulting from uniting the ends of different nerves ; he therefore kept them 
in contact — Union took place in every instance. In some of the cases, the return of the 
function was complete ; in others, it failed. In all, the transmission of irritations 
by the united nerves was perfect. — .A??!. Med. Journ. no. vii., May, 1829. 

(1) Arnemann, Versuche icber das Gehirn, und Ruckcnmark, Gottin"-en p. 187 

(2) The only case we know is that mentioned by Clarke, Phil. Transact 1793 p 
154-164. ' v ' 



OF THE NERVOUS SYSTEM IN THE ABNORMAL STATE. 197 

have described the brain. ( 1 ) We shall only say here, that the absence 
of the spinal marrow (at least such as might be considered original) 
has never been observed in a fetus where the brain was perfectly de- 
veloped, and that anencephalia is more frequent in the female than in 
the male. 

In regard to the nerves, they are rarely wanting. The first degree 
of this anomaly is the partial interruption of a nervous trunk ;(2) of this 
the nervous system of organic life (§ 182) sometimes furnishes exam- 
ples. 

The nervous system is never doubled, nor multiplied, at least when 
the body is not. 

2d. An excess or deficiency of volume. 

An excess in size is rare when the structure of the nervous system 
is otherwise normal. (3) As to the contrary state, an abnormal small- 
ness, although the nerves never are deficient, this is not more common 
than original deviations of formation. Atrophy or wasting of the ner- 
vous system is seen more frequently ;. it may be primitive, as in tabes 
dorsalis, or consecutive, and accompanied by the loss of the function of 
the organ. Thus, when the eye is destroyed, the optic nerve wastes. 
The nerve, however, then becomes not only thinner and finer, but its 
texture changes, it hardens, is grayer, and more transparent. 

We may here mention the dropsy of the nervous system, where the 
solids have not the same relation to the fluids, which often accumulate 
in enormous quantities. This state is congenital more frequently than 
it is developed after birth. In the first case, the whole nervous system 
is generally affected ; in the second, it is confined to some of its parts, 
principally to the encephalon ; its more intimate relations must be 
mentioned in the description of .the brain and nervous system. 

3d. Anomalies of situation and form, particularly if congenital, are 
very rare. These also belong to descriptive anatomy. Among the 
accidental, we should distinguish lacerations, to which the brain is ex- 
posed, from an effusion of blood within it. The changes which occur 
in this organ belong to special anatomy. 

§ 205. Among the alterations of texture of the nervous system, we 
mention: 

1st. Anomalies in the color. This is rarely seen, unless accompanied 
by other alterations of texture. The whole or a part of the nervous 
system, however, is more or less tinged with yellow in jaundice. 

2d. The abnormal softness and hardness exist alone or together ; so 
that one portion of the nervous system is much harder and another 
much softer than usual. 

Weinhold asserts that the nerves are unusually soft or fluid in persons 
affected with typhus. (4) The brain is sometimes softer and sometimes 
harder than usual in maniacs. Frequently, too, it is harder in some 

(1) See our Path. Anat. vol. i. p. 195. 

(2) See our Path. Anat. vol. i. p. 392. 

(3) See our Path. Anat. vol. i. p. 392. 

(4) Hufeland, Prakt. Bibliothelc, vol. xxxi. p. 501. 



198 GENERAL ANATOMY. 

points, and softer in others, in people disposed to epilepsy. In hydro- 
cephalus, its parietes are generally thinner and softer. 

§ 206. New formations in the nervous system are not rare. Repe- 
titions of the normal tissue are extremely uncommon. Bones and fat 
are the only parts, to our knowledge, which appear, sometimes in 
the substance of the brain, more rarely in the nerves around them. 
But it is by no means uncommon to find accidental osseous tissue in the 
dura mater. 

On the contrary, abnormal formations of different kinds are not rarely 
developed either in the substance or on the surface of this system, espe- 
cially on that of the brain. 

Encysted tumors connect these repetitions of the normal tissues with 
the new formations. They contain various liquids, and are more rare 
in the nerves than in the encephalon, particularly in the ventricles 
and choroid plexuses. 

Very hard rounded tumors, of a yellowish white color, perhaps like 
the fibro-cartilages, as they have a fibrous structure, are sometimes 
found in the nerves,(l) and also in the brain. When developed in 
the nerves they occupy the intervals between their fibres. 

The brain is also frequently the seat of white, hard, round tumors, 
very analogous to scrofulous tumors, which would doubtless be found 
also in other portions of the nervous system, if they were carefully 
examined. They are almost always united to the cerebral substance. 
Some other tumors, resembling fungous tumors, and which perhaps are 
a repetition of the mucous tissue, are more rarely found, but only in 
the brain. They are red, very vascular, soft, and adhere but slightly 
to the substance of the brain. 

Finally, loose hydatids develop themselves both in the ventricles of 
the brain, especially in the lateral ventricles, and even in its substance. 
In treating of the special anatomy of the nervous system, we shall 
examine these anomalies more in detail. 



OF THE SPECIAL ORGANIC SYSTEMS. 

§ 207. After the description of the general organic systems follows 
that of the special (§ 16). 

Among these we consider, 1st, The osseous system, inasmuch as 
several circumstances in the history of the other systems are to be 
fully understood only by an acquaintance with it, especially with its 
external form. 

(1) Cheselden, Anatomy of the human body, p. 256, tab. 28.— Home, An account of 
an uncommon tumor found in one of the axillary nerves, in the Trans, for the im- 
prov. ofmed. and surg. knowledge, vol. ii. no. xi.— Spangenberg, Sur les gonflemen* 
des nerfs, in Horn, Archiv. fur med. Erfahrung, vol. v. p. 306.— Alexander, De 
tumoribus nervorum, Leyden, 1800.— Wood, On painful subcutaneous tubercle, in 
the Edinb. med. and surg. journal, vol. viii. no 31 and 32. 



OF THE OSSEOUS SYSTEM IN THE NORMAL STATE. 199 

SECTION FOURTH. 

OF TH" OSSEOUS SYSTEM. 

§ 208. The bones(l) are solid parts, of a yellowish white color, con- 
nected by different kinds of attachment, and so firmly united as to con- 
stitute a whole, representing exactly the form of the body. They may 
be considered, 1st, In regard to themselves ; 2d, In relation to their 
connections with each other. 

ARTICLE FIRST. 

OF THE OSSEOUS SYSTEM IN THE NORMAL STATE. 
I. OF THE BONES. 

A. GENERAL REMARKS ON THE BONES. 

§ 209. The bones differ principally from other organs by great hard- 
ness and solidity, which permits them in a measure to form the base of 
the whole body. These qualities render them susceptible of forming 
levers, on which the muscles act to produce motion. Hence they may 
be called the passive organs of locomotion. 

§ 210. The great hardness of the bones is the immediate result of 
their chemical composition. In fact, they contain more of the phos- 
phate of lime than any of the organic parts. A chemical analysis of 
the bones proves that they are formed principally of two substances ; 
one soft and of an animal nature, the other hard and solid. The first 
is principally gelatin, hence the form of the bones, and their slight 
degree of flexibility. The other consists almost entirely of phosphate 

(1) Most authors, who have written on the bones, have not only described them 
generally, but also each particular bone. We shall mention here the former only. 
Some treat of the bones only in their normal state, as A. Monro, Anatomy of the bones 
and nerves, Edinburgh, 1726. — Cheselden, Osteography, or the anatomy of the bones, 
London, 1733. — Bertin, Traite de osteologie, Paris, 1754. — J. Sue, Traite de osteologie, 
with plates, Paris, 1759. — Blumenbach, Geschichte der Knochen, Gottingen, 1812. On 
the structure of the bones in general we may consult Malpighi, De ossium struc- 
turd, in his Opp. posth., Venice, 1 743.— D. Gagliardi, Anatome ossium novis inventis 
illustrata, Leyden, 1723. — Havers, Osteologia nova, or some new observations on the 
bones, London, 1691. — Description exacte des os, comprise en trois traites, by J.-J. 
Courtial, J. L. Petit and L. Lemery. — De Lasone, Memoire sur V organisation des 
os, in the Mem. de Paris, 1751. — J. F. Reichel, De ossium ortu atque structurd, 
Leipsic, 1760. — B. S. Albinns, De construction ossium, in the Annot. acad. lib. vii. 
c. 17. — Scarpa, De penitiori ossium structural commentarius, Leipsic, 1799. — Mala- 
carne, Auctuarium observationum ad ostcologiam et osteopathologiam L/udwigii 
et Scarpa, Padua, 1801. — As to the pathological anatomy of the bones, besides the 
works of Cheselden, Courtial, and Malacarne, the following are important to con- 
sult : A. Bonn, Descriptio thesauri ossium morbosorum Hoviani, Amsterdam, 1783. — 
Musceum anatomicum Ac. Lugd. descriptum ab. E. Sandifort, Leyden, 1793.— C. 
T. Clossius, Ueber die Krankheiten der Knochen, Tubingen, 1798. 



200 GENERAL ANATOMY. 

of lime. From the latest and most accurate analysis of Berzelius,(l) 
the bones contain, 

Of gelatin, completely soluble in water, 32,17 

" insoluble animal matter, 1 - 1 ^ 

" phosphate of lime, 5104 

" carbonate of lime, 11.30 

" fluate of lime, •■ 2.00 

M phosphate of magnesia, 1-16 

" soda and hydro chlorate of soda, 1-20 

The proportions of these constituent principles, however, vary both in 
the same bones of different men, and in the different bones of the same 
man, to say nothing of the variations dependent on age and the state 
of health. Thus the petrous portion of the temporal bone contains in 
general more earthy substance than the other bones. (2) 

§ 211. The color of the bones is yellowish white. We can make 
no general remarks in regard to their form ; they vary so much in this 
respect we are obliged to divide them into at least three classes, the 
long bones, the broad bones, and the short bones. All these bones dif- 
fer from each other, not only in form, but in texture : this, however, 
presents certain general conditions in all bones, which should be first 
studied, more especially as the three classes differ only by trifling 
shades. 

§212. All the bones resemble each other in texture, inasmuch as 
they are formed essentially of fibro-cellular tissue, of which the fibres 
and cells are closer, and consequently less apparent at the cir- 
cumference than internally. Hence we distinguish in the bones a 
cortical or compact substance, (substantia compacta sen corticalis,) and 
an internal called the spongy, or cellular substance, or the diploe, (sub- 
stantia spongiosa, cellulosa, s. diploe, s. meditullium) . But this distinc- 
tion is not essential : for 1st, it does not exist when the bones are 
formed, nor during the early periods of their existence, since we find 
only the spongy substance. 2d. We sometimes see the compact sub- 
stance change into a spongy substance, or at least all differences be- 
tween them are effaced when their vitality is exalted by disease. Far- 
ther, if the compact substance of regularly formed bones be treated by 
chemical agents, and the lime be removed, we recognize they are 
formed in the same manner as the diploe. Finally, there is always an 
inverse relation between the quantity of the two substances in differ- 
ent parts of the same bone ; that is, in thicker parts the compact sub- 
stance alone exists, or at least in greater proportion than the other, 

(1) See in Gehlen, Journal fur die Chemie, vol. iii. part 1. p. 1. However ac- 
cording' to the analysis of Fourcroy and Vauquelin, (Annales cle Chimie, vol.' 47, 
no. 141,) of Hildebrandt, (Schweigger, Journal fur Chemie unci Physik, vol. viii. 
part 1, p. 1,) human bones seem not to contain magnesia. 

(2) Several instances may be seen in Monro, ( Outlines of the anatomy of the hu- 
man body.) From the analyses of Davy in a subject, all the bones of the head con- 
tain more earthy substance than the long bones. 



OF THE OSSEOUS SYSTEM IN THE NORMAL STATE. 201 

while in the parts which aro more extended it forms only a thin layer, 
and incloses a considerable portion of the spungy substance. 

§ 213. The fibres and laminae which compose the bones are not 
simply applied one against the other, so as to extend the whole length, 
breadth, or thickness of a bone,(l) or to go from its centre to the cir- 
cumference. They incline so many different ways, one against the 
other, and unite so frequently by transverse and oblique appendages 
and processes, that great anatomists have been deceived by this ar- 
rangement, and have doubted the fibrous structure of the bones. Ne- 
vertheless, this conclusion is not perfectly correct. Notwithstanding 
those curves and anastomoses of the fibres, the fibrous structure 
always remains very apparent, and it is correct to say that the dimen- 
sion of length exceeds the other two in the texture of many bones. 
This predominance is very well marked during the first periods of 
osteogeny, for at a later time the fibres are so applied against each 
other that it is difficult to distinguish them. But these longitudinal 
fibres never exist alone ;(2) there are many oblique and transverse 
ones, from the first periods of ossification, and they ave even from the be- 
ginning so multiplied, that the number of longitudinal fibres is not so 
much greater as at a subsequent period, when the fibres approach 
nearer, so that the transverse become oblique, until at last, from the 
increase of bone, the latter at first view seems composed of longitudinal 
fibres only. The transverse and oblique fibres do not form a separate 
system ; they continue uninterruptedly with the longitudinal, which 
they unite to each other. 

§ 214. The fibres and laminae, arranged in this manner, unite in 
several superimposed layers, and form the thickness of the bones ;(3) 
these layers, it is said, are united only by fibres and intermediate 
laminos, the mechanism of which, according to Gagliardi,, who has im- 
perfectly described them, is very complicated. It is true that con- 
tinued maceration, the action of the air, and calcination, reduce the bones 
into several thin layers, adjusted to each other : it is also true that a 
part of a bone affected with necrosis is usually thrown off in a layer, 
varying in breadth and thickness ; but these three agents act too vio- 
lently and too destructively for us to draw any certain conclusion from 
the phenomena they produce. As to necrosis, the form of the sequestrum 
depends only on the extent and thickness of the diseased part. 

§ 215. The bones present eminences and depressions which differ 
much in form and importance. The eminences are of two kinds. 
One species serves for the insertion of the muscles or ligaments, and is 
consequently always connected with the fibrous organs, since the mus- 
cles are never attached to the bones but by a tendon. The others 
relate to the kind of motion performed by the bones. The former are 
usually rough and irregular, and are destitute of cartilage ; the latter 

(1) According to Havers, loc. cit. p. 33-37. 

(2) Hiklebrandt pretends that the transverse or oblique fibres are formed after 
them, (Anatomic, vol. i. p. 77, § 54.) 

(3) Gagliardi, Havers, Rcichcl. 

Vol, I 26 



202 CENEIUL ANATOMV. 

are smoother, more regular, and surrounded with cartilage. The emi- 
nences which project and are long in proportion to the bod_y of the bone, 
are usually called processes, or apophyses (processtis, apophysis); the 
tuberosities (tuber), and tubercles (iubercula), are those which are 
shorter, but broad and uneven ; the styloid process (stylus) is cylindri- 
cal and thin, and the spinous process (spina) is small, thin, sharp, 
and pointed ; the crest (crista) is more extensive, smooth, and strongly 
projecting ; rough lines (linece asperoz) are those which are extended, 
not very prominent, but so broad that we distinguish in them two lips, 
(labia,) as in some of the preceding. 

The apophyses are designated by terms drawn from certain analo- 
gies. Thus a round articular process is called a head (caput), and a 
condyle (condylus) when flatter. The heads and condyles are usually 
supported by a narrow portion of bone, called the neck (collum, 
cervix) . 

§ 216. The depressions serve for the articulations of the bones with 
each other, for the insertion of muscles and ligaments, for the pas- 
sage of vessels and nerves, or for the nervous system in general. 

The first are supplied with cartilages, the second are roughened, and 
the third are always smooth and more or less round. 

The glmoid cavity (caviias glenoidea) is a shallow articular ca- 
vity ; a deep one is called an acetabidum, or a cotyloid cavity, (cavitas 
cotyloidea.). The depressions, whether larger or smaller in the sub- 
stance of the bone, and which have a narrow orifice, are called sinuses 
(antrum, sinus,) or cells (cellula) according to their size. 

Most of those which serve for the attachment of muscles and 
bgaments, are called pits, (fovea, sinus.) 

Those which lodge vessels or nerves are sometimes narrow, and 
called grooves, (sulcus, semi-canalis,) sometimes they are broader, and 
called notches (incisura) when they occupy the surface only. When 
they traverse the bone from one part to another they are called fissures 
(fissura) or holes, (foramen,) according to their size : if they extend 
some distance they are called channels (canalis) or canals. 

We must here remark generally that the arrangement of the 
depressions for the passage of the nerves and vessels, is not always 
perfectly similar even in two sides of the same subject, since we some- 
times find a hole or canal on one side, while on the other is only a 
foramen. 

The different eminences and cavities are formed sometimes only by 
a single bone, sometimes by the union of pieces of several bones ; the 
first is more common. 

§ 217. Most of the important apophyses are formed by a special 
nucleus of bone which gradually unites with the rest of the bone, 
that is, with its body, and which is not entirely blended with it until the 
stages of its growth are completed. It is generally believed that the 
elevations and the depressions inthebones result from mechanical causes, 
from pressure and the traction of the organs which are attached to 
them, or which are there inserted. In fact certain circumstances 



OP THE OSSEOUS SYSTEM IN THE NORMAL STATE. 203 

seem to justify this explanation. Thus the corrugations for the inser- 
tion of the muscles are more apparent in proportion to the power of 
these muscles and their frequency of contraction : hence they are not 
very distinct in children, and always less so in the female than in the 
male. The origins of these corrugations are generally explained in 
this manner ; but the solidity and hardness of the bones do not allow 
us to admit such a theory ; probably the action of the muscles contri- 
butes only remotely to this result, increasing the nutrition in the whole 
part, and thus favoring the more perfect development of the bone. If these 
corrugations for the insertion of the muscles arose from a mechanical 
cause, we should not find depressions : but when examined with atten- 
tion we often find a cavity in which the' tendon lies, as is seen for ex- 
ample in the humerus, the radius, and the fibula. The depressions of the 
bones are produced immediately by the muscles opposing the develop- 
ment of the osseous substance in the place where they are inserted, so 
that when their activity is increased and their size augmented, the 
cavity of insertion becomes greater, because the development of the 
bone is prevented to a greater extent. 

This is the only way in which we can admit that the furrows, desti- 
tute of cartilages, in which the tendons glide, are partially pro- 
duced and enlarged by a cause purely mechanical. The tendon, which 
is formed at the same time as the bone, prevents the formation of the 
latter in the part corresponding to it, and opposes its development still 
more, in proportion as its surface is oftener compressed. 

The presence of a nerve or vessel opposes the accumulation of car- 
tilaginous or osseous substance in the part corresponding to it. The 
channels of the arteries are evidently caused by the pulsations of the 
vessels, which not only hasten absorption, but prevent the deposition 
of new nutritious matter. In the fetus, where the bones of the skull 
are united to each other less firmly, and do not inclose the brain so strong- 
ly, so that the vessels of the dura mater cannot press on them with so 
much force, the arterial channels are scarcely visible ; they are very 
slight and superficial during the first year ; but they gradually become 
deeper as the bones of the skull are more closely united, because the 
pulsations of the arteries then act on a single point. This is proved 
especially by the depressions, and even the openings in the bones of 
the skull, which correspond to the glands of Pacchioni, which must be 
considered as the remote cause of the disappearance of the bone in the 
places on which they act. 

But the cavities developed within the bone and which open exter- 
nally, as also those which communicate with the nasal fossae cannot 
be attributed to mechanical causes, though Ackermann has pretended 
they are produced by the air. They depend necessarily on the mode 
of development of the bones in which they are observed. This is de- 
monstrated because we trace them even in the fetus, because they are not 
developed in certain parts of the body to which the air has free access, and 
because their number, extent, and even existence in different animals, 



204 GENERAL ANATOMY. 

have not the least connection with the greater or less exposuro to tho 
air of the bones which contain them. 

§ 218. The organic tissues which form an essential part of the 
structure of the bones, are 1st, the periosteum ; 2d, the vessels; and 3d, 
the medullary system. 

§ 219. The periosteum belongs to the class of fibrous organs. 
(§16.) It covers the bones entirely, and is attached to them by a 
very short cellular tissue, and also by the vessels which pass into 
the bones. The only points to which it does not extend, are those 
where the bones articulate with each other : it there passes from one to 
another, either in one piece or in several distinct fasciculi. The first 
arrangement is seen in the immoveable articulations, and the second 
in most of the moveable joints. In several bones, but not in all, 
the fibres of the periosteum are parallel to those of the bones 
which it surrounds, and the external are more extensive than the inter- 
nal. The vessels ramify in its tissue before they penetrate the sub- 
stance of the bones. It furnishes prolongations which line their 
course, but which do not unite to the medullary membrane : hence it 
performs a certain part in the formation of the bone, and when 
destroyed to a considerable extent, that portion of the bone below it 
dies, although generally at the surface. In fractures, the osseous sub- 
stance is never regenerated until a new periosteum forms : thus it 
appeair first in parts most remote from the fracture, where the perios- 
teum has not been destroyed. These phenomena prove that the 
periosteum and bone are allied in regard to their mode of formation : 
but they do not authorize the assertion that in ossification the peri- 
osteum becomes bone. 

§ 220. The opinion that bone is formed by the change of the perios- 
teum, and not by the action of the vessels of this membrane, has 
been sustained by Duhamcl,(l) and rests on the following arguments : 

1st. In the fetus the periosteum of the same bone is membranous 
in some parts and osseous in others : it presents the first character in 
its extremities, and the second in its centre. It is thicker at the extremi- 
ties, and is there composed of several layers. (2) 

2d. Several prolongations of the periosteum penetrate between the 
apophyses and the body^of the bone : the whole apophysis is even 
formed by the periosteum, as are also the adjacent ligaments and 
tendons. (3) 

3d. In the fetus and during youth the apophysis is attached to the 
body of the bone by the periosteum alone, so that it is only necessary 
to remove this membrane to separate them. (4) 

4th. The different colors of the osseous layers, when the animal has 
or has not been fed with madder, demonstrate the same thing. 



(1) Memoir on the bones, Mem. 1 and 2, in the Mem. do Vac. des sciences. 1741 ; 
Mem. 3, ibid., 1742 ; Mem. 4-7, ibid., 1743. 

(2) Mem., 1743, p. 132-164. 

(3) Ibid., p. 163. 

(4) Ibid. 



OP THE OSSEOUS SYSTEM IN THE NORMAL STATE. 205 

5lh. Tho same remark applies to the formation of callus. There 
the periosteum swells around the fracture and becomes proportionally 
harder, especially in its inner part : during the first days, the hardened 
parts above the fracture may be removed with the periosteum ; afterward 
this operation is no longer possible, and there then remains a layer of 
bone, while a portion of the tumor may be removed with the periosteum. 
Sometimes the external periosteum unites with the internal to produce 
callus. 

6th. The periosteum is sometimes hardened in exostosis. 

§ 221. But Is., the statements under the first head are not perfectly 
true, for although in the fetus we always find a thin, gelatino-carti- 
laginous layer between the periosteum and the bone, this is never con- 
tinuous with the periosteum. We never find the periosteum osseous 
in one part and cartilaginous in another. 

2d. The prolongations sent by the periosteum into the bone, do not 
prove that these two organs are the same, and that the first is changed 
into the second. In fact, the periosteum is united more intimately to 
the cartilage than to the bone : but still this does not demonstrate the 
identity of cartilage with it and with the tendons. 

3d. It is not true that the cartilage is attached to the bone only by the 
periosteum, for even after this membrane is removed, continuity still ex- 
ists between the two organs as before, without any medium. 

4th. The difference in color of the layers of the bone prove only that 
the bone is formed by depositions from without. 

5 th. The phenomena of the formation of callus prove only that the 
periosteum inflames from the influence of a mechanical cause which 
has acted in it, and that a new substance forms between it and the 
bone, in which the new bone is developed, and which adheres to the 
latter. On the contrary, attentive examination of the formation of cal- 
lus demonstrates that in this case, as in that of primitive ossification, a 
cartilage is formed, in which a bone appears afterwards.(l) 

6th. The periosteum does not always thicken in exostosis, and even 
when this thickening occurs, it proves nothing, as it may be merely a 
new phenomenon. (2) 

Let us add also that bones often form without periosteum as in all ab- 
normal ossifications. 

§ 222. The vessels of the bones are not very large, and are general- 
ly of two kinds. Some arterial trunks, although few in number, pene- 
trate even the substance of the bones ; others ramify excessively in the 
periosteum before entering into their tissue. The first penetrate farther 
forward, and serve principally for the secretion of the marrow, or of a 
fluid analogous to it ; for whenever there is a medullary organ, they ex- 
pand in this membrane. They serve also to nourish the internal and 
looser tissue of the bone. The others remain in the external compact 
substance. These two orders of vessels, however, frequently anasto- 
mose together ; so that when the trunks arc obliterated, wc find their 

(\) Mem. 1711. 
(2) Ibid. 



206 GENERAL ANATOMY. 

branches and twigs full of blood, as in the normal state. There are 
as many kinds of veins to correspond to the different kinds of arteries. 
These vessels have also special holes through which they penetrate 
into the bone; those which give passage to the large trunks arc called 
foramina (foraminia nutritia) of nutritions, although this term is not 
exactly applicable.(l) Wc do not find lymphatics, except on the sur- 
face of the bones ; nor do we distinctly perceive nerves in these or- 
gans. 

§ 223. The marroiv(2) (medulla ossium) is inclosed within the bones; 
it is an oily or fatty substance, ai.-d its characters vary in different parts. 

In the cavities of the long bones, which are entirely filled, and hence 
are called the medullary canals,it is thicker, more solid, more yellow, and 

(1) The arteries enter the bones by three- divisions: 1st, by ramuscules, which fill 
the capillary holes of the surface of th»3 whole osseous system ; 2d, by branches which 
enter by larger foramina in the surfaces of the short bones and in the extremities of 
the long- bones ; 3d, by branches called nutritious, which penetrate the bones through 
the foramina of nutrition. The Istand 2d divisions of these arteries are mostly formed 
of capillary branches ; they penetrate the osseous tissue, pass through it, and termi- 
nate in it exclusively : these" are truly its arteries of nutrition. The 3d is com- 
posed of much larger branches, which proceed into the internal cavities of the bones, 
through the canals of nutrition. The branches which compose it are distributed to 
the medullary membrane, and seem unconnected with the nutrition of the osseous 
tissue, which they do not penetrate. 

The first two divisions are not accompanied with any vein. We observe them, 
On the contrary, around the third, and they correspond exactly to the number and 
volume of the arteries which compose it ; but they arc not sufficient to return all tho 
blood distributed to the bones by the three kinds of arteries, and carry back that 
only which was brought to the vascular membrane. The proper veins of the osseous 
tissue were discovered by Dupuytren (Prop, sur quclques points & anatomic, dephys. 
et d' anatomic path., Paris, 1803) in the bones of the skull. They have since been re- 
cognized in all the other bones of the body, whence they emerge by numerous open- 
ings of a diameter sufficiently large, through which we do not observe that any arte- 
rial ramification enters, even after the most successful injection ; they are observed 
particularly in the flat and short bones, and in the extremities of the long bones. At 
some distance from where they emerge from the bones they terminate in the venous 
system. They arise from the osseous tissue by numerous radicles, which unite, like 
those of common veins, to form twigs, branches, and trunks, which, after passing 
through the spungy tissue, leave it, and penetrate the compact tissue to open into the 
adjacent veins, by a canal always smaller than that of which it is the termination. 
The osseous canals, through which they pass, are formed of compact tissue, which ap- 
parently extends from the surface of the bones to their interior. In these canals, di- 
rectly covered by the membrane of the veins, are numerous channels, through which 
the simple veins pour the blood which had existed in the osseous tissue. As to the 
veins themselves, they arc composed simply of the internal membrane of the venous 
system, folded into numerous valves. They have no cellular membrane externally. 
They resemble, then, the venous sinuses of the cerebrum, as the fibrous envelop 
furnished to the latter by the dura mater is replaced by bony walls, on the surface 
of which the thin, transparent, and unresisting internal membrane is closely applied, 
so as not to admit of motion, nor to exercise any action on the blood which traverses 
the venous canals. 

There i3 a remarkable analogy between the spungy tissue of the bones and its 
venous canals, on one part, and the corpora cavernosa of the penis and clitoris, 
on the other. In fact, the veins are arranged to form the corpus cavcrnosum of the 
penis exactly in the same manner as the spungy tissue of the bones of the skull, au< I 
of the extremities of the long bones. Replace the osseous cells by a fibrous nctwi nk, 
and line this network by the inner membrane of the veins, and we have an exact 
idea of the arrangement of the corpora cavernosa. In sonic annuals, the fibrous tis- 
sue does not exist, and the cavernous tissue is formed only by the veins, which then, 
by their numerous communications, resemble the spungy or reticulated tissue of the 
bones. F. T. 

(2) Grutzmachcr, Dc ossium medulla, Leipsic, 1758. 



OF THE OSSEOUS SYSTEM IN THE NORMAL STATE. 207 

contained in a proper and very thin membrane, which forms numerous 
small vesicles. Like the fat, it is composed of round globules, often 
varying in size ; so that the medullary organ seems to be only a por- 
tion of mucous tissue. The membrane which contains the marrow 
has been called the internal periosteum ; but it is distinguished from the 
true periosteum, the fibrous periosteum, although it resembles it in its 
. great vascularity. In fact, it is in this that the nutritious vessels of 
the bones are expanded. (§ 222.) 

The marrow of the broad, irregular, and short bones, that also in the 
ends of the long bones, differs much from that contained in the bodies of 
the long bones : 1st, because it is not surrounded with a membrane; 
2d, because it has less consistence, and contains less fat ; 3d, because 
it has a reddish color. It appears to be in immediate contact with the 
osseous tissue, and to arise from the vessels which penetrate within the 
bone. 

We have not been able as yet to discover nerves in the medullary 
membrane ; but, from the experiments of Duverney(l) and Bichat,(2) 
confirmed by us, it seems to be very sensible. Bichat says its sensi- 
bility is more marked as we approach the exact centre of the bone. 
We have not foimd this to be the case. (3) 

While the bone is cartilaginous, there is no appearance of marrow. 
We cannot say, with Bichat, that the medullary organ exists before 
the canal, and that it is filled only with a cartilaginous substance, 
which is afterwards replaced by the marrow. 

The marrow does not develop itself till ossification commences. But 
several years after birth it is much redder and more fluid than in the 
adult, and not fatty. 

This state reappears in disease, especially when nutrition is inter- 
rupted to a great degree, as in patients affected with phthisis. 

The functions of the marrow are very obscure. 

We may consider it as diminishing the brittleness of the bones. 

It is difficult to decide if its uses relate directly to nutrition. Some 
have thought this to be the case, because bones die when the marrow 
is destroyed ; but this conclusion is not correct, since this phenomenon 
may depend solely on the intimate organic connection between the two 
organs. 

We think the existence of the marrow is connected with the whole or- 
ganism, rather than with one bone in particular, and, like the fat con- 
tained in the rest of the mucous tissue, that it is a provision of nutriment 
in reserve. 

(1) De la struct, et du sent de lamocllc, in the Mem. de Paris, 1700. 

(2) General anatomy, vol. iii. p. 112. 

(3) Experiments and pathological observations leave us in doubt in regard to the 
sensibility of the marrow, which some authors, and Bichat among the rest, have 
much exaggerated. Lebel, while extracting a sequestrum five inches long, most of 
which comprised all the thickness and all the circumference of the tibia, was obliged 
to tear the medulla, the surface of which was flesh-colored. He did not irritate it to 
discover to what extent it was sensible, but held it for some seconds ; the sick person 
did not complain ; and he wa3 unable to determine what part it could take in the 
pain of extracting the sequestra. The medullary membrane was inflamed, and 
therefore was more sensible than intho natural state.— Journ. compl., vol. v. pp. 312, 
313. P. T 



208 GENERAL ANATOMT. 

§ 224. Although the bones are hard and solid, they have a certain 
degree of elasticity ; this property varies according to circumstances. 
They cannot change their volume by the action of irritating sub- 
stances, but have the power of extending and contracting to a certain 
degree. This change, however, is not transient : when they extend, 
there is almost always an increase in their mass ; and when they con- 
tract, there is a diminution in volume. The first case takes place when 
they are mechanically extended, and depends on a separation of their 
constituent molecules. The other seems to take place even when there 
is an increase in mass ; for instance, when a distended bone collapses, ■ 
and an opening is obliterated by the wasting of the nerve or vessel 
to which it gave passage. A similar phenomenon is observed when 
the alveolar processes are absorbed after the extraction of the teeth. 

Tn the normal state the bones have no animal sensibility ; for the in- 
juries which affect them cause no pain. Facts which seem to prove tho 
contrary have been furnished by bones not entirely formed, or which 
are diseased, conditions in which sensibility is highly developed in them. 

§ 225. This circumstance seems to contribute, at least in part, to 
the slowness with which ossification takes place. The bones are of 
all organs the last to appear, and arrive at perfection, either in the ani- 
mal series or in the fetus ; all their diseases progress slowly, compared 
with those of other organs. But, on the other hand, this circumstance 
contributes to render ossification the most perfect of all the formative 
acts of the body ; for no other solid possesses the power of reproduction 
in so great a degree. Not only is a simple fracture united by a sub- 
stance which, in form, chemical composition, and functions, is almost 
identical with the normal osseous substance, but portions of bone and 
whole bones, after having been destroyed, are repaired, not in fact in 
their form, but in their volume, their relations with the adjacent parts, 
and their functions, of which we shall treat more particularly when 
speaking of the anomalies of the bones. 

§ 226. The bones, both in respect to form and chemical composition, 
pass through several periods of formation before attaining their term of 
perfection, ; and when they have reached it, they descend from it by 
several successive changcs.(l) The changes which occur in them, 

(1) Sue, Sur les proportions du squclctte de Vhommc, examine depuis I'ugc Ic plus 
tendrejusq'd eclui de vingt-cinq, soixante ans, ct au-deld, in the Mem. pros, d I' Ac. 
des sc., vol. ii., Paris, 1755, p. 572-586. — H. Eyssou, Tractatus de ossibus infantis 
cognoscendis, conservandis, ct curandis, Groningen, 1659. — V. Goiter, Tractatus 
anatomieus de ossibus fxtus abortivi, ct infantis dimidium annum nati, Groningen, 
1659. — R. Nesbitt, Human osteogeny, London, 1753, in 8vo. — J. Easter, De ostcogenia, 
Leyden, 1731. — A. Vatcr, Ostecg-emajWittcmberg-, 1735. — B. S. Albinus, hones os- 
tium foetus, Leyden, 1737. — J. A. Ungebauer, De ossium trunci carp. hum. cpiphysi- 
bus sero osseis visis carumdemque genesi, Leipsic, 1739. — B. S. Albinus, I. De gene- 
rations ossis. II. Quccdam de prima ossium natura disccptatio, in Annot. acad., 
1. vi. — Idem, De gcncralionc ossium, in Ann. acad., 1. vii. no. 6, 1764 and 1766. — 
Perenotti, Memoirc sur la construction ct sur V accroisscmcnt des os, in Mem. de Tu- 
rin, vol. ii. 1784. — C. F. Scnft', NonnvMa de incremenlo ossium cmbryonum imprimis 
graviditatis mensibus, Halle, 1781. — J. F. Meckel, Considerations anat. ct phys. sur 
les pieces osscuses qui enveloppcnt les parlies centrales du syst. ncrv., in the Journ. 
compl., vol. ii. p. 211. — M. Troja, Oascrvazioni cd csperimenli suite ossa, Naples, 
1814. — M. Medici, Espcricnze intorno alia tessitura organica dcllc ossa, in the 



OF THE OSSEOUS SYSTEM IN THE NORMAL STATE. 209 

from their first appearance to their period of perfection, are remarkable, 
because their different periods of development correspond, and often with 
surprising exactness, to permanent states in animals. Like all other or- 
gans, the bones are softer the nearer the fetus is to its origin. At first 
they are not firmer than the other parts. In a few weeks they harden; 
and are then cartilaginous, and become more and more consistent. 
The cartilages which at this period occupy the future places of the 
bones differ from the latter, as their structure is not fibrous, and as we 
can perceive neither cellules nor medullary cavities, and as they con- 
stitute a solid and entirely homogeneous mass ; but this mass possesses 
the external form of the bone, and like it is covered with a periosteum. 
Towards the eighth week the vessels of some of these cartilages com- 
mence carrying red blood instead of the colorless liquid they hitherto 
contained. It is then that ossification really commences. First the 
cartilage becomes softer and looser, always at its middle part ; it disap- 
pears finally, and in its place we see a fibro-cellular tissue, composed 
of gelatin and phosphate of lime. This change into cartilage and 
bone, does not commence in all the bones at once ; but there is 
this constant relation between these two acts, that the bones whose 
cartilages appear first are the first to ossify, and that in each bone in 
particular the first osseous germs are found precisely in the points 
where the cartilages first show themselves.(l) 

There are but a few bones formed of a single nucleus. In most of 
them we see different and separate osseous germs, which are connected 
together for a longer or shorter period only by cartilage, and which 
are gradually united ; so that it is only when the whole body has 
acquired its growth that all traces of the primitive separation are 
effaced. In certain bones, as the sacrum, these traces never disappear. 
In regard to the order of ossification for the different parts and for the 
whole bone, there are general laws with respect to the form, size, and 
number of the nuclei of bone, and to the period when ossification com- 
mences, either generally or particularly ; but we cannot discover the 
general cause of the succession to which entire bones and their different 
constituent parts are subjected in their appearance. 

§ 227. The general laws of osteogeny are : 

Opusculi scienlifici, Bologna, 1818, p. 93-107. — Medici, Considerazioni interho alld 
tessatura organica delle ossa, in riposta alio oppos.fattc del S. D. C. Spetariza et dal 
S. A. Scarpa, Bologna, 1819. — Rapporl de Cuvier sur le Traite des lois de I'osteogcnie, 
by Serres, in the Journ. com.pl., vol. iii. p. 67. — Lebel, Reflexions sur la regeneration 
des os, same journal, vol. v. p. 309. — Schultze, Considerations sur les premieres traces 
du systeme osseux, same journal, vol. vi. p. 113.— Bcclard, Meinoire sur I'osteose, in 
the Nouv. journ. de medecine, vol. iv. 1819. — Dutrochet, Observations sut I'osteoge- 
nir, in the Journ. de physique, 1822, Sept.— See also the first note to this section. 

(1) J. Howship has remarked that in many bones, especially in the diaphyses of the 
loner bones and the central portions of the broad bones, ossification takes place im- 
mediately, that is, the osseous state is not preceded by cartilage. (See his Micro^ 
scopical observations on. the structure of bone, in the Medico-chirurg. trans., vol. vi.-x, 
London, 1815-1819.) Beclard, (Gen. Anat., trans, by Togno,) admits this opinion, and 
describes the progress of ossification very precisely in the following passage : " Ossi- 
fication does not every where result from the transformation of cartilage into bone'. 
The diaphysis of the long bones and the centre of the broad bones, which are de- 
veloped at a very early period, pass immediately from the mucous to the osseous 
Vol. I. 27 



210 GENERAL ANATOMY. 

1st. Ossification commences in the substance of the cartilage ; so 
that the nucleous of bone is entirely surrounded with cartilage. 

2d. Ossification begins in the centre of the whole bone and of each 
nucleus of bone. The bones increase from within outward ; so that 
the external layers appear after the internal. This arrangement is 
demonstrated by experiments made by feeding animals with madder. 
When killed after this substance has been mixed with their blood, the 
internal surface of the bone is always white, the external red. We 
may in this manner produce a number of layers alternately white and 
red, by suspending and resuming the use of madder.(l) Still the sub- 
stance of the internal layers is also constantly renewed ; for if we kill 
an animal which is at first nourished without madder, but to whom the 
coloring matter is afterwards given, and then suppressed, the internal 
part of the bone is alone found- red, and the external is white.(2) 

The bones increase in length and breadth ; so that the new sub- 
stance is not only added to their extremities and edges, but penetrates 
the mass already existing. In truth, Hunter, having observed that 
two holes made in a long bone of a young animal were not separated 
from each other by its growth, has deduced another conclusion ;(.'*) 
but Duhamel's experiments, which were made previously and with 
greater care, prove that the English anatomist was wrong, and that 
the development of the bones at the centre is much slower and ar- 
rested much sooner than at their extremities. (4) 

3d. In the successive formation of the different parts of bone, (§ 226,) 
the largest appear the first. We should hence conclude that the 
largest bones are those which are first seen. But although, if we 
except the teeth and the small bones of the ear, the small bones appear 

state. The other parts of the system are at first cartilaginous, and in them the suc- 
cessive phenomena of ossification may be best observed. The cartilage, which for a 
longer or shorter period takes the place, and performs the functions, of the bone of 
which it has the form, and of which it gradually acquires the volume, is at first hol- 
lowed with irregular cavities, then witn canals lined by vascular membranes filled 
with a mucilaginous or viscous fluid ; it becomes opaque, its canals become red, and 
ossification commences towards its centre. The first point of ossification (punctum 
ossificationis) always appears in the substance of the cartilage, and never at its sur- 
face. It is surrounded by red cartilage at the place which is in contact with it, 
opaque and full of canals at a little distance from it, and at a still greater distance 
homogeneous and without vessels, but only perforated with canals of blood-vessels 
which tend towards the osseous centre. The osseous point continually increases by 
growth at its surface, and also by interstitial addition in its substance. In proportion 
as the bone increases, the cartilage, successively perforated by cavities and canals 
lined by sheaths and blood-vessels, gradually diminishes, and at length disappears. 
The canals of the cartilages themselves, which are very wide at the commencement 
of ossification, become smaller and smaller, and at length disappear when it is com- 
pleted. In the place of a cartilage more or less thick, but at first full or solid, with- 
out cavities and without distinct vessels, at a later period perforated with canals 
lined by vascular and secreting membranes, there is found a very vascular bone, full 
of areolar or spungy cavities, invested with membrane, and filled with adipose mar- 
row. The bone afterwards becomes less vascular as age advances." K. T. 

(1) Duhamel, Sur le (level, et la crue des os. in the Mem. rte Paris, 1742, p. 497, 
498. 

(2) Home, Exp. and obs. on Die growth of bones, in the Trans, for the imp. of 
med., vol. ii. xxiii. 

(3) Trans, fur the imp. of med., vol. ii. p. 279. 

(4) Cinquieme mcmoirc'sitr les os, in the Mcm.dc Paris, 1743, p. 187, 188. 



OF THE OSSEOUS SYSTEM INT THE NORMAL STATE. 211 

later than the large bones, we also remark that the middle-sized bones 
are usually formed before the largest. Thus the scapula, the bones of 
the pelvis, and the long bones of the extremities, appear long after the 
clavicle and the lower maxillary bone are formed; and there is a 
period when the clavicle, which in a full-grown man is scarcely one 
fourth of the size of the humerus, is equal to six times its volume. 

4th. The bones and their different parts arrive at perfection in the 
order of their formation. Thus the two arches of the vertebra appear 
long before the body, and their posterior extremities are fused together 
long before the anterior unite to the body. 

5th. The cylindrical bones, with few exceptions, form and are per- 
fected before the flat bones, and the latter before the short bones. Thus 
the clavicle, the ribs, the lower jaw, and the large bones of the extremi- 
ties, are very far advanced when scarcely any traces appear of the 
occipital and frontal bones, which are fiat bones, and the only short 
bone visible is the upper jaw. This law applies also to the consti- 
tuent parts of the different bones. Several short bones, especially 
those of the carpus or the tarsus and the patella, contain no nucleus of 
ossification in the full grown fetus, and it is only at the sixth month of 
pregnancy that ossification commences in the sternal cartilage. The 
body of the cylindrical bones and the arches of the vertebra are formed 
and developed much sooner than the processes of the former and the 
bodies of the latter: but the parts which are here the last to appear corre- 
spond to the short bones in every respect. This law is very remarka- 
ble, because it is intimately connected with the power of reproduction 
in the different bones. In fact, the bones which are formed and de- 
veloped the soonest are the most easily and the most completely 
reproduced when they have been accidentally destroyed: the flat 
bones are reproduced with more difficulty than the long bones, and the 
short bones, slower than all the others. These two conditions' seem to 
depend on the law, that the organic formation is founded on a force not 
differing from that on which the electrical phenomena depend, and 
which acts principally in the direction of the length. 

6th. The order in which the bones are developed in the human 
fetus seems to depend on that according to which they appear in the 
animal series. We cannot doubt this in regard to the jaws and clavi- 
cle, which are so highly developed in the fishes, nor to the sternum, 
the bones of the pelvis, and the other bones of the extremities, which 
are developed so imperfectly in the fishes and the cetaceee. 

7th. The destination of the bones appears to exert some influence 
on the rapidity of their formation and development. This is instanced 
in the early appearance of the jaws, which are so much needed, and 
the slow development of the sternum and bones of the pelvis, which 
are the last to arrive at perfection, because the cavities which they cir- 
cumscribe must necessarily be closed late. 

8th. The same relation does not exist in the development of all the 
bones in regard to form and volume. In certain bones, particularly the 
long bones, the different pieces composing them do not unite until they 



212 GENERAL ANATOMY 

begin to increase in length, or even till this is finished En others, 
such as the short bones, several flat bones, and some irregular bones, 
all the parts are united long before the bones have attained their lull 
growth. Even at the age of twenty, maceration detaches the epi 
physes from the bodies of the long bones, while the pieces of the sphe 
noid, frontal, and occipital bones and of the vertebrae are united in the 
early periods of existence. 

9th. The mode of development of each bone, in relation to its 
appearance and completion in the form and volume of its pieces, is in 
general subject to laws ; but there are also exceptions to these laws, 
and these are more numerous in some bones than in others. Of fell 
bones the sternum presents the most numerous and the greatest varia- 
tions in regard to the number, size, form, and situation of the osseous 
nuclei which gradually produce it, and even also in regard to the time 
of their appearance. This phenomenon is more remarkable, as the ster- 
num is the very last bone which appears ; whence these variations in 
its formative type seem to occur, because the energy of the formative 
power begins in some measure to be exhausted. The bones too which 
form the arch of the skull are less constant in their development, since 
it is not rare that some of their component pieces are developed sepa- 
rately, and never unite to the others, which explains the formation of 
,the ossa wormiana. 

10th. The chemical composition of the bones is not the same at 
all periods of life. In general we may state as a principle, that the 
earthy substance is less in proportion to the animal parts, the younger 
the bone is. In a person even fifteen years old the proportion of the 
earthy to the animal substance was found to be nearly one fifth less 
than in an adult.(l) 

11th. The structure of the bones is looser, more spungy, and softer 
in infancy, which coincides perfectly with their chemical composition. 
Thus, at first appears only a simple tissue of fibres and layers differ- 
ently interlaced, in which there is no hard substance. 

12th. As to the external form, the bones are rounder and less hard 
and angular in infancy than at a more advanced period ; their emi- 
nences and depressions are also much less marked. In general, there- 
fore, their surfaces are smoother and more uniform. 

13th. The bones are more flexible and elastic in youth than in ad- 
vanced age. Hence why external violence produces at this period 
only slight changes, curves, and impressions, while they afterward give 
rise to solutions of continuity. Hence fractures are more common in 
aged people. 

§ 228. The great difference in every respect between the cartilage 
and the bone has induced anatomists and physiologists to seek out 
the cause of the change of cartilage into osseous tissue. To explain 

(1) Davy (in Munro's Anatomy of the human body, Edinburgh, 1813, vol. i. p. 36.) 
found, for instance, that the femur in a child fifteen years old was composed of .53 
of animal substance and .47 of earthy substance, and in an adult, of .375 of animal 
matter and .625 of earthy matter. 



OF THE OSSEOUS SYSTEM IN THE NORMAL STATE 213 

tins phenomenon satisfactorily, two problems must be resolved, viz. 
1st. On what ground is there a period when cartilage is changed into 
bone? 2d. How does this change take place? It is more than 
doubtful if the first question is ever resolved with certainty. The 
phenomenon to which it relates belongs to a general law of every 
organized formation, that the fluids predominate the more, the nearer 
the fetus is to its origin. We may attach to the second, two 
different senses, and ask either a simple statement of the phenomena 
presented by the change of cartilage into bone, which has been treated 
of above, or the indication of the means by which this change takes 
place. But we cannot explain this phenomenon more readily than 
that of the successive changes which supervene in all the other organs. 
Besides, it is very singular that we should be lost in conjecture only in 
regard to the formation of bone, and that all the other organs, which 
present as great differences at different periods of kfe, are entirely neg- 
lected. The only thing certain is that all the theories of ossification 
are either vague or false ; and that in the latter case, the more mecha- 
nical they are, the farther they are from the truth. Of this character 
are the following : that the arteries are filled with osseous juice, which 
obstructs and tears them ; that the arteries of the cartilages gradually 
ossify ; that bone takes the place of cartilage ; that the periosteum 
gradually changes into bone ; and that the cartilage is only penetrated 
by the osseous substance. Ossification essentially consists in the 
formation of a new organ different from cartilage. It is then an act 
of nutrition of an entirely different character which acts upon this 
part of the organism. The existing matter is taken up more rapidly 
in some places than in others; hence the formation of a medullary 
canal and of cellular and spungy tissue, instead of a solid, homoge- 
neous, cartilaginous substance. But at the same time the act of nu- 
trition itself changes ; since a medullary organ and fibres composed 
of gelatin and phosphate of lime are formed. This change depends on 
that which occurs in the activity of the instruments of nutrition, the 
vessels designed for bringing and carrying away the nutritious fluid. 

§ 229. When the bones have acquired their normal situation, and 
the different pieces which gradually unite to form them are fused in a 
single mass, they increase more or less in thickness also. 

§ 230. But the thickness of the bones diminishes much in old 
age;(l) so that they lose their weight, and break more easily, as 
much for this reason as because they have become more fragile. The 
greater fragility depends principally on an increase of earthy matter ; 
for dead bones are broken more easily in proportion as they lose their 
animal substance. Davy found in the occipital bone of an adult 64.0 
of earthy matter, and 69. in that of an old man. (2) Still this rule 
does not seem to apply to all bones ; at least Davy found that the 

(1) F. Chaussard, Recherches sur I' organisation des vieillards, Paris, 1822. — Ribes, 
*yur les changemens que le tissu osseux svbit paries progtes de Cage et Virtfiuericcde 
diverses maladies, in the Bull, de lafac de mid., vol. vi. p. 299. 

(2) Davy, loc. cd., p. 36. 



214 GENERAL ANATOMV 

lower jaw of an old person where the alveolar processes were entirely 
effaced contained 43.4 of animal substance and 56.6 of earthy matter, 
while the relation between these two substances was as 42.8 to 57.2 
in a child, and as 40.5 to 59.5 in an adult ;(1) but the lower jaw of 
the old person was more fragile. 

§ 231. The sexual differences of the bones are generally the greater 
thickness, asperity, and prominence, of the processes in man ; the small- 
ness and roundness of their form in woman. But many of the bones differ 
also in the two sexes very strikingly : a change of form coincides with a 
difference of function, as especially in the bones of the pelvis. But these 
differences can be examined only in special anatomy. So too, and 
with greater reason, it is with the difference of races, as they appear 
principally in the form of the different bones. 

B. PARTICULARS OP THE DIFFERENT CLASSES OF BONES. 

§ 232. The different classes of bones, (§ 210,) beside the general 
characters of bones, present certain peculiarities which deserve to 
be studied. 

§ 233. The long bones are those in which the dimension of length 
much exceeds the other dimensions. We find the extremities {apo- 
physes) broader than the central part, the body (diaphysis) ; this 
increases their lightness and their articulating surfaces, and renders 
luxations more difficult. The body is generally cylindrical, but we 
can almost always easily distinguish three faces, separated from each 
other by more or less acute edges. Some of the long bones form, in a 
measure, the transition from this class to that of the flat bones ; for, 
although long and narrow, they are not thick ; whence they appear 
not round, but flat : such are, for instance, the ribs. The lower jaw 
resembles the flat bones still more. The bodies of these bones are 
never perfectly straight, or at least except in rare cases, and only 
during the early periods of life. They are usually a little arched or 
curved, and do not possess the same thickness in every part. The form 
of the extremities of each long bone varies according to its uses ; it is 
in direct relation with the greater or less degree of mobility in the limb 
whose base it constitutes. As to their internal composition, these 
bones are peculiar ; as their body is more or less hollowed, and the 
medullary organ exists in their cavities. These cavities are not found 
towards the extremities of the bone ; but in their place there is a loose 
fibro-cellular tissue, which seems developed at the expense of the com- 
pact substance ; since the latter diminishes, and is insensibly reduced 
to a thin layer, in proportion as the spungy substance accumulates ; 
while in the centre, where the latter does not exist, it is very solid, and 
it is one or two lines thick in the largest long bones. The ribs 
and lower jaw, which by their external form mark the transition of the 
proper long bones to the flat bones, differ also from the real long bones 

(1) Davy, loc. cit,, p. 36. 



OF THE OSSEOUS SYSTEM IN THE NORMAL STATE. 215 

by the absence of a medullary cavity. They are entirely filled with 
spungy tissue. 

The long bones are principally found in the limbs, of which they 
form the base. They diminish in volume, and increase in number, as 
their distance from the trunk increases. The number, form, and other 
relations of these bones are essentially the same in the corresponding 
parts of the extremities. The upper parts are the most movable ; still 
those which form the first articulation of the fingers and toes are 
more movable than those of the middle and anterior. 

The cylindrical bones are generally formed of three pieces. We 
however find more in several of them. Of these pieces, one corresponds 
to the body, the other two to the extremities. The central piece 
developes itself long before the other two, and at the exact centre of 
the bone, in the form of a thin straight cylinder. The extremities do 
not ossify till after birth, and are not completely fused with the body 
until its growth is perfect. The spungy substance is not however con- 
fined to their inner parts : it appears also in the extremities of the body 
properly so called ; but here it is finer and longer, and consequently 
is more fibrous, than in the extremities. 

§ 234. The flat bones are nearly as broad as long, but they are less 
in thickness. Most of them are more or less convex on one face, and 
concave on the other : their outer and inner faces are usually parallel. 
This form depends on the functions they fulfill ; for they serve espe- 
cially to form cavities, which arise from a certain number of flat bones 
solidly articulated to each other. Many of them, especially those of 
the cranium, are surrounded with teeth, which, penetrating reciprocally, 
form the most solid species of articulation. These bones are not much 
thicker on the edges than elsewhere ; the other flat bones, however, 
resemble the long bones, inasmuch as their edges are very thick, par- 
ticularly in those points where they articulate to each other, and also in 
those where muscles are attached to them. 

The compact and spungy substances are uniformly extended every 
where in the flat bones. The compact substance forms an internal and 
an external layer or table, (tabula vitrea,) between which the spungy 
substance (diplooi) is formed. In a few of the flat bones, especially the 
smallest, as the ossa unguis and the lower portion of the septum bone 
of the ethmoid, the spungy substance is deficient ; and here the two 
tables are blended together into one. The proportion between the 
inner and outer substances is not the same in all. Thus, for instance, 
in the ossa ilia the external is much thinner and feebler, and the internal 
looser, than in the bones of the skull. 

Still there are cavities more or less extensive in some flat bones ; but 
their uses are not the same as those of the cavities found in the long 
bones. They are not filled with marrow, but contain air, open ex- 
ternally, and are appendages or prolongations of the nasal cavity. 

Most of the flat bones arise by several points of ossification, which 
form one after another. There are at least two lateral nuclei, which 
unite sooner or later on the median line, as we see in the frontal bone, 



216 GENERAL ANATOIM* 

and even to a certain extent in the parietal bones. But in some others 
also these lateral parts gradually develop themselves by several points, 
as in the occipital and sphenoidal bones, the ossa ilia, and the scapula. 
Here likewise, as in the long bones, the apophyses, which correspond to 
the short bones also, constitute at first as many distinct pieces of bone. 
The flat parts also, which may generally be termed the scaly or squa- 
mous portions, (squammce, partes squammosa;,) arise from several se- 
parate nuclei. The different nuclei of these bones almost always join 
in the articulations, where ossification takes place last, while when the 
pieces touch in other parts, they soon unite. This arrangement is seen 
in the development of the coxal bones (ossa ilia) and of the occipital 
bone, where it seems to favor the enlargement of the articular cavities, 
and perhaps depends partly on the mechanical action of the bones arti- 
culated on this point. The flat bones are formed not only by the suc- 
cessive union of several pieces of a certain extent, which remain sepa- 
rate a longer or shorter time : there are developed also at the circum- 
ference of the largest nucleus of bone, along its edge, and at various 
times, a number of other germs, which are entirely distinct, and very 
different in respect to number, size, and situation, and which 
gradually fuse with each other and with the principal piece, which 
primitively existed. Sometimes these small nuclei, and even larger 
pieces, those which are formed after a more constant type, remain 
insulated, abnormally : thus we see different kinds of wormian 
bones appear, which result for the most part from the development 
being suspended, and which occur most frequently in the parts where 
several bones come together so as to leave between them vacant spaces 
called fontanclles. 

§ 235. In the short or thick bones no one dimension much exceeds 
the others. Their form is more or less rounded, and they are also dis- 
tinguished from the other bones by their greater irregularity. In their 
tissue they resemble the flat bones and the extremities of the long 
bones, as they have no cavity, and the compact substance is every 
where filled with spungy substance. T'hese bones are always united 
in great numbers, either lengthwise, as in the vertebral column, or 
breadthwise, as in the tarsus and carpus, and are so disposed that as a 
whole they have extensive motions, while they move upon each other 
but slightly. This is in part the ground of their great irregularity of 
form ; for their surfaces present numerous elevations and depressions, 
which serve for the attachment of the ligaments. Some of these bones 
have a more complex form than others ; and the same is true of their 
functions : thus each vertebra has a large opening, and resembles a 
ring, because intended not merely as a lever for the attachment of 
the muscles which are there inserted, but also as the reservoir of an 
organ, the spinal marrow. • 

There is a particular class of short bones, the sesamoid bones, 
which we shall mention when speaking of the fibrous system. 

§ 236. Besides these classes of bones there is still a fourth, which 
may be called the mixed bones, for they seem produced by the blending 



OF THE OSSEOUS SYSTEM IN THE NORMAL STATE. 217 

of bones of several classes, principally of the second and third, being 
composed of flat and short portions. The sphenoid, temporal, and eth- 
moid bones are examples of this class ; even the occipital bone belongs 
to it. The vertebrae mark the transition between it and the class of 
short bones. These bones are always developed by several nuclei, one 
of them having the characters of the short bones, and the others those of 
the flat bones. The latter are usually more numerous than the others. 
Almost all these bones inclose cavities which communicate with the 
nasal fossae. 

Finally, we will remark that comparative anatomy proves that the 
same bone changes its form in different animals in such a manner that 
it belongs to another class. These differences are not then very 
essential, and depend on the whole form. 



II. OP THE ARTICULATIONS OP THE BONES. 

§ 237. The articulations of the bones differ much in respect to their 
modes of union and to the extent of motion they permit. It is a gene- 
ral law, but subject at least to one exception, that the corresponding 
portions of bone are covered with cartilages (5th section) or with fibro- 
cartilages, (6th section,) and that accessory fibrous ligaments (7th 
section) extend from one bone to another, which circumscribe and 
cover the points surrounded with cartilage. 

§ 238. Generally we may consider the difference of mobility and 
the arrangement of the modes of union as furnishing the base of a 
classification of the articulations. Still they are not perfectly identical, 
since the same degree of mobility may be obtained by different means. 
Thus, the bones which articulate by straight and even, or by very un- 
even surfaces, but which correspond perfectly, although not united, and 
which are firmly attached by very short and tense ligaments, have as 
little motion as those whose surfaces adhere to each other in all their 
extent by means of a mass of cartilage. 

The best mode of classifying the articulations is according to the 
forms of their corresponding surfaces, and also to the arrangement of 
the means of union j since on these depends the difference in their 
degree of mobility. 

§ 239. The forms of the corresponding surfaces, and the arrange- 
ment of the means of union, are such that the bones can or cannot 
play upon each other. In the first case, the surfaces not covered with 
cartilage are not united except at their circumference, and there is no 
mean of union between them ; this is called a movable articulation. 
In the second case, a cartilaginous or fibro-cartilaginous mass extends 
from one surface to the other, and unites them together j this is called 
an immovable articulation. 

§ 240. The movable articulation, or the joint, (articulus, junc- 
tura, diarthrosis,) presents several varieties, depending on the form 
of the contiguous surfaces. These maybe referred to five principal 
forms : 

Vol. I. 28 



218 GF.NEIIAL ANATOMY. 

1st. The loose joint, (arthrodia,) where a largo globular extremity, 
or a head, fits a plain surface of small extent. . The articulation of this 
species possessing the most motion is that of the humerus with the 
scapula. We must refer to the same class those of the fingers and 
toes with the carpus and tarsus, and the. radius with the humerus. 
Other things being equal, the motion is more free as this head is larger 
in relation to the surface to which it is applied, and as the head is 
rounder, and this surface is flatter. Farther, the form of the articular 
surfaces being the same, the degree of motion varies much, according 
to the tension and the greater or less number of the ligaments. 

2d. Enarthrosis is where a large head corresponds to a deep 
rounded cavity. Many anatomists do not consider this species as a 
separate articulation, but call it an arthrodia. The articulation of the 
femur with the iliac bone and of the lower maxillary bone with the 
temporal bone, are examples. Here too the motions are freer, more 
capable of being performed in all directions, and more extensive in 
each direction, as the contiguous surfaces are rounder. 

3d. The t ur ning joint, or hinge joint, (ginglymns.)(l) It consists 
in such an arrangement of the articular surfaces as will admit of mo- 
tion in only one direction ; so that the bones can only approach and 
recede from each other, be flexed or extended. This effect is produced 
in two modes. Sometimes a simple surface having an oblong protu- 
berance corresponds to another surface which presents the same form 
hollowed, and from one of the bones a considerable process extends on 
each side, which permits no motion except that from before backward : 
such is the articulation of the foot. Sometimes one of the articular 
surfaces has two lateral heads, separated by a large hollow ; and that 
which corresponds to it presents on the sides two hollows, between 
which is an elevation : we see an instance of this in the articulation of 
the humerus with the upper extremity of the ulna, and in that of the 
femur with the tibia. The articulations of the first phalanges with 
the second, and of the second with the third, of the fingers and toes, are 
between these two forms. We see in the first, the middle cavity and 
the eminence which corresponds to it are replaced by external pro- 
cesses. Still the articulation of the first offers a slight and indistinct 
index of the second form. 

4th. The rotatorxj joint, (rotatio, diarthrosis, trochoides.) The cor- 
responding surfaces are small sections of a cylinder, and one of the ' 
bones turns on its axis, at the same time revolving on that of the bone 
with which it articulates. But the motion is never sufficiently free for 
one of these bones to turn entirely on its own axis ; and even where 
the arrangement of the surfaces would permit it, as, for instance where 
the articular surface of one of the bones extends all round its extremity 
there are other arrangements, dependent on the structure of the bone 
itself, which permit it to make at most but a semi-revolution on its axis. 
We see instances of this joint in the articulation of the upper and lower 
extremities of the radius with the ulna, and that of the first cervical 
vertebra with the odontoid process of the second. 

(1) Isenflamm resp. Schmidt, Dc ginghjmo, Erlangen, 1783. 



OF THE OSSEOUS SYSTEM IN THE NORMAL STATE. 219 

5th. The last kind of this movable articulation is the close joint l 
(amphiarthrosis, diarthrosis,s.juncturastricta, ambigua, synarthrotica.) 
Two straight or differently formed articular surfaces, having numerous 
elevations and depressions which exactly correspond, are forcibly 
applied against each other by short ligaments, which go from the cir- 
cumference of one to that of the other. The usual consequence of this 
arrangement permits only an almost imperceptible sliding of the con- 
nected surfaces. This kind of articulation belongs particularly to the 
short bones, which unite to form in some measure a single bone flexible 
in several parts. We see it in the carpus, the tarsus, the vertebral 
column, and the ribs. 

§ 241. The immovable articulation (synarthrosis) also offers several 
varieties in its form and degree of immobility. As the corresponding 
osseous surfaces are generally united in all their extent by a carti- 
laginous or fibro-cartilaginous mass, they etui never glide upon each 
other : still the bones are sometimes slightly displaced, from the length 
and elasticity of the mass which unites them, and the flatness of their 
corresponding surfaces. Several anatomists admit also a third kind of 
articulation, between the movable and the immovable joint, called the 
mixed, or semi-movable, (articulatio mixta, amphiarthrosis, symphysis.) 
But, as this articulation is essentially the same as the immovable in 
respect to the arrangement of the uniting substance, and as the articu- 
lations which become immovable by age were at first movable, when, 
the intermediate mass being softer and larger, the extremities of the 
bones were placed at a greater distance from each other, it appears 
more proper to consider the mixed articulation only as a species of 
synarthrosis. The different varieties of the latter are, 

§242. 1st. Symphysis. It consists of two plain surfaces, united by 
a mass more or less thick and elastic, which allows them to separate 
and approach each other insensibly. When this intermediate mass is 
cartilaginous it is called synchondrosis, and synneurosis(l) when it is 
ligamentous or fibro-cartilaginous. The articulation of the different 
parts of the sternum is an instance of the first, and that of the ossa 
pubis and of the ossailia with the sacrum, of file second. 

§ 243. 2d. The suture, (sutura,)(2) an articulation found only in the 
head. It consists essentially in the union of long narrow surfaces or 
edges by a very thin layer of cartilage, whence results an entire want 
of motion. The degree of this immobility varies with the arrangement 
of the contiguous surfaces. The principal kinds of sutures are, 

a. The false suture, or harmonia, (harmonia, sutura spuria,) in 
which edges perfectly straight, or at least but slightly serrated, are con- 
nected : such are the ossa unguis and ossa nasi with the adjacent 
bones and with each other. 

(1) This is not the usual acceptation of this word ; but we ought not to attach any 
other meaning to it when we wish to mark the two kinds of symphysis by the nature 
of the mass which unites them. 

(2) Duverney, Lcttrc concernant plusieurs nouv. obs. sur I'osteologie, Paris, -1689. — 
Bo3C, De suturarum cranii humani fabricatione el usu, Leipsic, 1755. — Gibson, On 
the use of the sutures in the skulls of men and animals, in the Mem. of the society of 
Manchester, second series, vol. i. 1805, p. 317-328. 



220 GENERAL ANATOMY. 

b. The true suture, (suhira vera,) which also presents several varie- 
ties, according as the joint becomes more solid from tho multiplicity of 
the points of contact. 

Immediately after the harmonia comes, 

1st. The scaly or squamous suture, (sutura squammosa.) The sur- 
faces of the two adjacent bones are gradually formed like a swallow's 
tail, the one being sloped to receive the other for a considerable extent. 
At the same time the contiguous surfaces are more or less serrated, 
but the processes are feeble : we will mention as an instance the arti- 
culation of the temporal bones with the occipital bone. 

2d. The serrated suture, (sutura serrata.) Small and plain pro- 
jections and cavities alternate with each other, both from above down- 
ward and across, along the perpendicular and narrow edge, and corre- 
spond to similar cavities and processes of another bone ; so that each 
bone presents a double range of elevations and depressions. The upper 
part of the frontal suture is almost always formed after this type. 

c. The dentaled suture (sutura denticulata) also arises by single 
processes and cavities, which alternate with each other on a perpendi- 
cular edge ; but the elevations are higher and the cavites deeper, and 
they form only one series. We see an instance of this arrangement in 
the sagittal suture. 

d. The margined suture (sutura limbosa) much resembles the pre- 
ceding ; but the processes and cavities are larger, and are often subdi- 
vided. It sometimes happens also that the processes of one bone are 
fitted obliquely to those of another. Still the first condition is the most 
essential, as the second also occurs more or less in the preceding 
sutures. The occipital suture belongs to this series. 

Here we must observe that these four kinds of sutures with teeth pass 
from each other by insensible shades. Thus, the inferior part of the 
frontal suture generally makes the transition from the squamous to the 
dentated suture, since the frontal bone glides under the parietal bone to 
a considerable extent ; but the oblique portion by which the two bones 
are united is separated from the rest of the surface by a very sensible 
prominence, and its internal part is in fact perpendicular. 

We find also in the same suture different parts, each of which be- 
longs to the last three sutures, and others which cannot be referred to 
any. We should particularly consider that the same suture does not 
belong to the same class in all skulls. The sagittal and even the 
lambdoidal suture is sometimes only a dentated suture, while the 
frontal suture is often a very complex margined suture, and in 
other cases extends almost in a straight line. Even the squamous 
suture of the temporal bones is sometimes changed into a dentated 
suture. Generally, when one suture is more complex and conse- 
quently more solid than usual, the others are so in the same proportion 
and vice versa ; so that the bones of the skull are articulated more 
firmly in some subjects than in others. It is also a rule, that one and 
the same suture is far more complex on its outer than on its inner face 
where it usually forms nearly a straight line. 



OP THE 08SEOUS SYSTEM IN THE NORMAL STATE. 221 

The sutures are found only in the head, and arise necessarily from 
the manner in which the bones of that part are developed ; for ossifi- 
cation commences there in several points at once, and the bones increase 
by the addition of new osseous substance to their outer circum- 
ference. Hence also they are often effaced in one point or another 
when the bones are entirely developed. Before this period the dentated 
edge which exists in them, and by means of which the parts of bone 
are attached to each other, is very impoitant to the solidity of the arti- 
culations. Thus we find similar irregularities on these surfaces of 
bone, not provided with cartilage, which are joined so as to glide 
slightly on each other : as the bones of the pubis, the iliac bones, &c. 

§ 244. 3d. Gomphosis is where a bone implants itself like a wedge 
in the cavity of another, which embraces it closely, envelops it in most 
of its length, and retains it very solidly, although they are not united. 
This kind of articulation is seen only in the head : the insertion of the 
teeth in the jaws is an instance. 

§ 245. The movable articulations do not change much during life, 
while those which are immovable, as at least the sutures and gom- 
phosis, vary considerably. In the early periods, large spaces, filled by 
the internal and external periosteum, exist between the bones which 
are separated by a layer at first thin and mucilaginous, and after- 
ward cartilaginous. Still their edges are more unequal during the 
early periods of uterine existence than in the adult, because the rays 
of bone which leave the point of ossification to go there are very 
numerous, and separated from each other. But this form does not 
seem to prove that the tendency to produce these sutures is mani- 
fested from that time, since at an earlier period, when the edges of 
the bone are already approximated, they are much straighter, and even 
more so than when the development is perfect. The edges do not 
even touch in a fully grown fetus, and we observe between them, in 
those parts where the several angles of the bones are afterwards 
united, large spaces called fontanelles, (fonticuli, fontes pulsatihs.) 
Even after the bones are in contact with each other, we may establish 
as a general law, that the sutures gradually become more complex by 
age, and acquire still more solidity, not only by the increase of the 
principal processes, but by the formation of secondary processes on 
their surfaces. 

This union of the bones by sutures, which becomes in time more 
and more intimate, finally degenerates into complete fusion. There 
are general laws for the manner in which this fusion takes place, and 
the greater or less frequency with which certain sutures disappear ; 
but there are none for the period at which it commences. 

The general law relative to the manner in which this fusion occurs 
is that the internal edge of the sutures disappears before the external 
edge. It is a common thing in young subjects to find all the sutures 
of the head effaced internally, while they are perfectly preserved ex- 
ternally. We never observe an opposite arrangement. So, too, one 
suture never disappears in all its extent at once ; but obliteration usu- 



222 GENERAL ANATOMY. 

ally commences at a single point, whence it gradually extends to the 
whole suture. 

In regard to the second general law, the bones of the face are blended 
together much more rarely than those of the skull. Even among the 
latter there are some which are united much oftener than others. But 
we shall reserve the details on this subject for the section in which we 
shall examine the bones of the head particularly. 

What proves the impossibility of assigning any general law in re- 
gard to the period when the obliteration of the sutures commences, is 
that they are sometimes found entirely effaced in the fetus at birth, 
that they are sometimes though rarely fused during the early years of 
life, and that they are not unfrequently perfectly preserved in old sub- 
jects ; generally, however, the suture disappears only at the latter 
periods of life, while they fuse partially on the internal face very soon 
after the individual is perfectly developed ; and also in most subjects 
who have attained' the age of thirty, the whole suture or some parts of 
it disappears on this side. 

Gomphosis changes very much during life ; for the teeth are at first 
much smaller than the cavities which receive them, and which do not 
as yet compress them. 



ARTICLE SECOND. 

OF THE OSSEOUS SYSTEM IN THE ABNORMAL STATE. 
I. OP THE BONES. 

§ 246. The bones not unfrequently vary from the normal state in 
respect to all their characteristic qualities. 

The primitive deviations of formation(l) are not equally common in all 
the bones. Those of the cranium, and among them the occipital bone, 
are those which offer the most, and the bones of the extremities those 
which present the fewest. These defects of formation consist generally 
in a suspension of the development ; and their frequency must at least 
be ascribed in part to the circumstance, that in many animals, even 
those allied to man, the bones of the skull seem to stop regularly at 
these degrees of evolution. It is, however, remarkable, on the other 
hand, that the bones of the face usually vary little from the normal 
state to produce analogies with animals : for instance, the perfect 
development of the intermaxillary bone is very rare. It is not probable 
that such a difference depends on the high perfection of the brain of 

(1) Sandefort, De ossibus, direrso modn, c solita covfurmatione abludentibus, in the 
Obs. anat. "path., lib. iii. c 10, lib. iv. c. 10, p. 136-141. — Van Doeveren, Observations 
osteologicm, varios natures lusus in ossibus humanorum corporum exhib., in the Obs. 
acad. specim., Leydcn, 1765.— Rosenmiiller, De ossium varietatibus, Leipsic, 1804. 



OP THB OSSEOUS SYSTEM IN THE ABNORMAL STATE. 223 

man, since the anomalies of the skull are generally attended with the 
imperfect development of this viscus.(l) 

§ 247. The deviations in formation of thebones which may supervene 
at all periods of life are, first, solutions of continuity. 

The bone is broken either by a cutting instrument, when there is a 
wound, or by a bruising body, which causes a. fracture, (fractura.) 

The solution of continuity may be total or partial. The fracture is 
transverse, oblique, which is most common, or longitudinal. When 
the development is perfectly complete, they supervene with equal 
facility in all parts of the bone ; but when the epiphyses are not yet 
united, they are usually detached by mechanical lesion, or by those 
diseases which destroy the tissue of the bones. (2) 

The parts may heal in both cases, not merely when there is simply 
a solution of continuity, but also a comminuted fracture, when the bone 
is broken into several pieces, and there is a considerable loss of sub- 
stance. The detached fragments sometimes unite, even when placed 
in contact with healthy portions. 

The progress of formation is exactly the same as in normal ossifica- 
tion.^) A gelatinous substance is effused around and between the 
fragments, which gradually hardens, and becomes cartilage, within 
which several nuclei of bone afterwards appear, which fuse with each 
other and with the broken parts, surrounding those also which have 
been perfectly detached. At the same time the fragments and splinters 
become round, so that the adjacent parts may not be wounded by their 
asperities. (4) To produce this formation of new osseous substance, it 

(1) Mo3tof the principal deviations of formation in the bones are mentioned in the 
first volume of our Pathological Anatomy, under the heads Anencephalia, Hydroce- 
phalus, Hernia cerebri, &c. 

(2) Reichel's monograph on this subject is excellent, Dc epiphysium ab ossium 
diaphysi deductione, Leipsic, 1769. 

(3) Boehmer, De ossium callo, Leipsic, 1748. — Id., De callo ossium e rubiae. tincto- 
rum pastu infectorum, Leipsic, 1752. — Haller, De ossium formatura, in the Opp. 
min., vol. ii. p. 46Q, — P. Camper, Observationes circa callum ossium fractorum, in 
the Essays and observations phys. and liter., vol. iii., Edinburgh, 1771. — Bonn, De 
ossium callo annex, ejusd. descr. thess. oss. morb. Hovian, Amsterdam, 1783. — A. H. 
Macdonald, De necrosi et callo, Edinburgh, 1799. — Beclard, Propositions sur quel- 
ques points de medecine, Paris, 1813. — Breschet, Quclques rccherches historiques et 
experimental sur le col, Paris, 1819. — J. Sanson, Expose de la doctrine de Dupuy- 
tren sur le col, in the Joum. univ. des sc. med., vol. xx. p. 131. 

(4) The most ancient explanation we possess on the mode in which these solutions 
of continuity of the bones unite, attributes thi3 consolidation to a kind of viscous 
fluid, more lately termed the osseous juice, or the coagidablc lymph. According to 
the ancients, this fluid exuded from the surfaces of the fracture, gradually be- 
came consistent, and reunited the fragments in the same manner as isinglass unites 
two pieces of wood. This opinion prevailed in the schools until the middle of the 
eighteenth century, when it was opposed by Duhamel, who published the results 
of his experiments. Bailer's opinion was like that of the ancients. He thought to 
gain more knowledge by experiments, which were made by Dethlef under his direc- 
tion, and which confirmed him in his opinion. He ascribed the callus to a juice 
coming from the fractured surfaces and from the marrow, a fluid which is effused 
around the fragments, gradually thickens, becomes cartilaginous, and then 
osseous, while the periosteum does not concur to re-establish the continuity of the 
broken bone. Haller, in describing the mode in which callus is formed, says that 
this operation resembles ossification; that the effused gluten, coming from the ves- 
sels or tissues of the broken surfaces and from the marrow, soon becomes consistent, 



224 GENERAL ANATOMY. 

is not necessary that the corresponding faces of the layers of bone, 

and assumes the characters of cartilage ; that this cartilaginous substance passes to 
the slate of bone when its vessels are sufficiently dilated to allow the red blood to 
penetrate its thickness, and brings a saline matter which forms osseous points, which 
successively are increased in extent, and finally pervade all the cartilage. In ano- 
ther place, Haller pretends there is from the commencement a gelatinous matter, 
and shortly afterwards a cartilage, within which a ring forms, which ossifies the 
first, extends to the processes, and breaks the cartilage, which retreats before it, and 
of which it is divested as of an envelop. This last mode of considering callus is 
very incorrect, and it will be easy for us to show it. Macdonald asserts that all the 
authors who have written before Haller, and even this great physiologist himself, are 
deceived when they pretend that the gelatinous matter of callus changes into car- 
tilage. Haller, however, does not exactly say it forms cartilage, but that at a cer- 
tain period we see organic molecules appear, which are not blood, and that when all 
the gelatinous mass has become opaque and elastic, it is then regarded as cartilage. 
Macdonald seems to think that the gelatinous substance never changes into carti- 
lage, but that the matter considered as cartilaginous is a real, soft, flexible bone, 
which is afterwards hardened by the phosphate of lime. He thinks, from his expe- 
riments, that the newly formed bone is originally soft, elastic, easily divided, and 
curved, in a word, that it resembles cartilage. The proofs brought forward to de- 
monstrate the osseous nature of this substance are that in nourishing an animal with 
madder, the callous substance reddens ; but this phenomenon does not appear in the 
cartilages. He supports his opinion too by the chemical analyses of the cartilages 
made by Allen. Finally, he has discovered the error into which Duhamel has fallen 
in attributing the formation of callus to the ossification of the periosteum. John 
Hunter, whose talent lias thrown light upon so many points of physiology, considers 
callus as the result of the organic development of extravasated blood, and of its transi- 
tion to the state of bone. J. Howship has lately developed Hunter's ideas more fully, 
and supported them with experiments. Hunter asserts that at first the space 
between the fragments of the bone and the surrounding parts is filled with blood 
coming from the ruptured vessels, that this blood coagulates, and that by an organiza- 
tion vessels areformed in it. Adhesive inflammation takes place at the ends of the frac- 
tured bones, and then a peculiar process commences. Inflammation supervenes also 
in the splinters which are still attached to the bone and the surrounding parts. It 
produces in ^hem a disposition to interstitial absorption, by which the angles of the 
Fragments are smoothed down, their extremities soften, and become conical ; now 
all these changes favor the ossification which is about to commence. Howship 
admits that Hunter's ideas are more correct than all which has been said in respect 
to callus, and that they agree in several essential points with his experiments. The 
conclusions he draws from his own researches are, that the first effect of the fracture is 
the extravasation of blood in the thick parts around, and that this varies in quantity 
with the degree of contusion or of complication. This blood is effused principally 
in the tissue of the periosteum, and increases its thickness. It is effused also 
in the medullary canal and between the fragments, where it is variously changed, 
and becomes the centre in which the ossification of the callus commences. The 
red color which pervades the periosteum gradually disappears; this membrane 
becomes firmer, and by degrees assumes the appearance of cartilage. The mode of 
progress in this union of fractures seems to show that the principal object is to pre- 
vent all possibility of motion between the parts. The callous matter is deposited on 
the surfaces of the bones, near the parts where union ought to take place, then on 
the circumference of the ends of the fragments and in the medullary cavity. The 
deposit of the blood, and the successive degrees through which it passes before it 
becomes an osseous substance, are remarked on the circumference of the ends of the 
fragments sooner than in the spaces which separate them. To give the ideas of the 
author better, we shall say that the fracture by this process becomes very solid 
before the union or the osseous cicatrix between the fragments is finished. In this 
respect Howship agrees perfectly with Dupuytren and also with Breschet ; and we 
would remark that these facts had been published in France, either by Dupuytren or 
Breschet, and after numerous experiments, before the appearance of Howship's me- 
moir. Finally, we say that if the fracture be compound, the vital operations to 
repair the injury are divided : on one side callus is deposited, on the other we see a 
manifest attempt to remove all the parts of the bone which have been separated, and 
where the circulation no longer exists. This elimination is conducted by the internal 
surface of the periosteum, which becomes granulated, extremely vascular, and pos- 



OF THE OSSEOUS SYSTEM IN THE ABNORMAL STATE. 225 

which are separated from each other, should be in contact ; for the 

eesses a great absorbing- power. The analogy between this theory and the ancient 
mode of considering callus has caused us to speak of it in the same paragraph. Du- 
hamel believed that the periosteum is to the bone what the bark is to the tree, and 
that tractures are often united by the agency of the membrane of the marrow. He 
thought it was the swelling of the periosteum and of the membrane of the marrow, 
their extension from one fragment to another in order to join and unite by ossification, 
which produced callus, and formed around the fractured bones sometimes a single 
sometimes a double ring, which fixed them firmly while it united them. This opin- 
ion has many advocates and many critics ; still we must acknowledge the exactness 
of many observations of Duhamel, and admire in his experiments a precision not to 
be expected from a stranger to medicine. Duhamel's theory, although false, has 
doubtless been useful to science, as it has drawn the attention of physiologists to the 
cicatrization of bones, and we owe to it the researches of Hallcr, Dethlef, Bordenave, 
Troja, &c, on the same subject. Fougeroux adopted, without any restrictions, the 
ideas of Duhamel, and endeavored by his experiments to reply to the attacks of Hal- 
ler and Bordenave. The opinion defended by him was no longer quoted, except as 
matter of history, when Dupuytren revived Duhamel's opinion, and extended his 
ingenious theory to observations on pathological anatomy. He has known not 
only the periosteum to ossify, but also the laminar tissue, the ligaments, and even 
the fleshy part of the muscles, to form a sort of osseous ring, which kept the frag- 
ments together, and preserved their relations. According to Dupuytren, we must 
admit two distinct epochs in the formation of callus, or rather two calluses which 
succeed each other in their formation. The first, which he calls the provisional 
callus, is completed when the medullary system of the two fragments is united, and 
a kind of osseous button exists within them which joins them, and the periosteum 
has formed externally, either alone or with the cellular tissue and even with the 
muscles, a ring which surrounds the extremities of the fragments, and adheres to 
them. Hitherto, the surfaces of the fracture are not yet united, nor even altered in the 
midst of the newly formed osseous tissue which constitutes the first callus. The soli- 
dity and resistance of the latter are less than those of the bone ; hence if a new frac- 
ture occurrs in the same bone, it will be exactly where the first existed. When, after 
four or five months at most, the medullary canal begins to form again in the part 
where it was obliterated ; when the accidental osseous substance produced by external 
ossification contracts and diminishes in volume ; when the periosteum, the cellular 
tissue, and the muscles, return to their natural state, or cease to be ossified, if the 
adaptation be perfect, and if there be no irregularity between the fragments ; finally, 
when the union takes place in the two ends and even on the surfaces of the fragments, 
then commences the second callus, or the definitive callus, which is not perfected till 
after eight months. This last period is characterized by the return of all the parts 
to their primitive state. This theory, however, which resembles that of Duhamel in 
several respects, since it assigns the periosteum as the seat of callus, differs from it 
much. In fact, Duhamel did not consider the osseous state of the periosteum as a 
provisionary state, while Dupuytren regards it only as a means to oppose the dis- 
placement of the fragments, and to favor the formation of the proper callus. He ad- 
mits and demonstrates that fractures are united by two successive calluses, the one 
temporary or provisional, occurring on the outside of the bone and in the adjacent 
tissues, the other definitive, and situated in the medullary canal and at the ends of the 
fragments, as well as in the space which separates them. Dupuytren's theory is of 
the highest importance in its practical application to surgery, as it throws much 
light on the treatment of fractures. Bordenave was the first who regarded callus as 
a cicatrix analogous to that of the soft parts, that is, a cicatrix produced by granu- 
lations which proceed from one fragment to meet those of another, unite, and then 
receive the calcareous salt which gives the character of bone to the substance of the 
cicatrix. At first, the bones pour out from their broken extremities a fluid which is 
the primary matter of their union. This fluid gradually thickens, assumes the form 
of bone, and when the dilated vascular tissues furnish vessels which open in it, the 
canal becomes similar to the bone itself. Some modern authors, as Bichat and Rich- 
erand, have also regarded callus as a cicatrix analogous to that of the soft parts, and 
depending upon the development of granulations which unite, and receive the phos- 
phate ol lime, to reestablish the continuity of the osseous tissue. Callisen thought 
that callus was formed by vessels arising from the broken extremities, and extend- 
ing between the fragments, and by the final deposit of osseous matter, that is, of the 
phosphate of lime. He explained by an enlargement of the vessels the union in a 

Vol. I. 29 



226 GENERAL ANATOMY. 

cure is as perfect when they are simply at the side of each other, pro- 
single callus of adjacent bones fractured simultaneously, as is sometimes seen in the 
leg and fore-arm. Bonn rigorously omits all explanation, and confines himself 
to the statement of what he has observed. His remarks rest entirely upon dis- 
sections of human bodies, and on a large number of wet or dry morbid preparations. 
Bonn does not appear to have experimented on animals; but he has sought to en- 
lighten himself by analogy and by facts observed by others. He maintains that cal- 
lus while imperfect is ligamentous and membranous. Callus, he says, at first resem- 
bles flesh ; it then acquires the consistence and tenacity of leather. But its transition 
to bone is never preceded by the formation of real cartilage. Perfect callus is organ- 
ized and identified with the bone : sometimes it is found entirely soli I, as in diseased 
bones, and again it is softened and dissolved by caries. J. Bell describes callus as 
being formed at first by a soft and flexible substance, situated between the fragments 
which it unites. It is the reestablishment of the continuity of the vessels of the bone 
which produces it. Samuel Cooper, adopting all J. Bell's opinions, defines perfect 
callus to be a new bone, or osseous substance, which unites the ends of a fractured 
bone. Peter Camper thought that in the union of fractured bones the fragments 
united by a double callus, one external, formed from gelatin furnished by the vessels 
and osseous fibres, which condenses below the periosteum, and afterwards becomes 
osseous substance ; the other internal, produced by the lengthening and separation 
of the inner layers of bone, or the expansion of the compact tissue of the bones, to 
obliterate the medullary canal. Troja has seen the ends of a fracture covered in a 
few days with gelatinous matter, which soon became abundant, and was gradually 
converted into cartilage, then into bone. He has also observed, a swelling of the 
periosteum till a certain period when the thickness of this membrane diminishes, an 
internal ossification filling the medullary cavity near the fracture, and an external 
ossification which always exists. The facts related by Troja are strictly correct ; a 
careful observer, he states candidly what he has seen, and does not, like Duhamel, 
follow a favorite and exclusive idea. The results of his experiments are similar in 
many respects to those obtained by Breschet. 

Having thus briefly stated the different opinions of authors with regaVd to the forma- 
tion of callus, we shall now mention the principal facts established by the numerous ex- 
periments of Breschet, premising, however, that the apparent discrepances in the opi- 
nions of writers in regard to callus, gradually disappear when its peculiar nature is stu- 
died. We then easily discover the cause of error, and the points where observers have 
fiven too great latitude to isolated facts, or have admitted them as general. Per- 
aps, also, as Beclard says, the differ'erices of opinion arise from the fact that the 
researches have not been made at every period, or at the same periods of union of the 
fractures. Breschet considers callus as depending, 1st, on the extravasation and the 
coagulation between the fragments of a little blood furnished by the ruptured ves- 
sels. 2d. On a fluid at first viscid, secreted and effused between the periosteum and 
coming from the neighboring tissues more or less connected in the fracture of the 
bone, and also from its broken surfaces. This formative lymph, (which may be com- 
pared to that exhaled from the edges of a wound of the soft parts, or that produced 
from several surfaces by inflammation, and which constitutes the membranous forma- 
tions,) is at first mixed with a little blood ; but afterward it is secreted alone, and when 
the periosteum is altered or destroyed, it is effused or filtrates into the interstices of 
the fibres of the soft parts around the fracture, and there thickening, forms a callus 
external to the fracture. 3d. On the gradual thickening of these fluids, (the blood 
and the formative lymph,) they unite gradually, and form stronger adhesions be- 
tween the parts, which inflame and become real secretory organs. Considering 
abstractly the inflammation of the tissues near the fracture, we may compare 
the viscid fluid mixed with a little blood and its successive changes, to the 
camb of plants, and the changes which this organic principle of vegetables pre- 
sents when effused between the bark and the woody part, or when secreted to 
cicatrize the wounds of vegetables. 4th. On the swelling and moderate inflam- 
mation of the periosteum and adjacent soft parts, on the cicatrization of these 
parts, and sometimes on the deposition of matter within their layers. 5th. On 
the contraction of the central cavity of the bone, on the softening of the ends 
of the fragments, and on the deposit of a substance similar to that which collects in the 
periosteum, or in the plates of the tissues adjacent, in the medullary "cavity, and 
between the ends of the fragments. 6th. On the condensation of this matter, on 
its organization by the development of the vessels. At first it has a granulating ap- 
pearance, it then assumes a fibrous consistence, next a cartilaginous appearance, and 
finally becomes bone. These changes are observed, first, external to the fragments, 



OF THE OSSEOUS SYSTEM IN THE ABNORMAL STATE. 227 

vided no foreign substance is interposed between them and that tbev 
are kept in contact It matters little, too, whether S^fente iSch 
are approximated belong to the same or to different boneT h^ure 
is not less perfect ; only anchylosis exists.(l) ' CUre 

InalLthese cases the extremities of the bones become round and 
are completely closed.. The bone becomes entirely solid where it' was 
fractured, and its medullary cavity is divided into two halves Hence 
a single bone in fact forms two. It is more solid in the 'place of 
he fracture, than in any other part, so that it is rare that a bone breaks 

™.£S^SSh^ the llfe of the — ^ 

i e establishment ot the medullary canal, and this canal is re-established onlv when 
te osseous subs ance by which the extremities are joined, is entirely solid Vhen 
pears"' /£ SSSLS"? ""? ^'^ ^ ^ du ^ diminishes, ana finally disap! 
Rnt ff*i the , fra - nen , ts have been accurately joined and there is no displacement 

Fratment re th e eni SP en f i e of e H t f *? * the ^ ° r direCti ° n «f the axesTf thTtwo 
„f?u i j n . the eiK 3 ^ f the fracture continue closed, the medullary canal is not 
re-established, the newly formed external osseous matter instead of befn- "bsorbed 
remains to strengthen the callus, and its greatest quantity corresponds to the portion 
where there is the most displacement, and where the efforts to be resisted by tfe bone 

uE2?* 8? *? eBt r^ ien r Seek t0 Com P are the development of callus wtth 
the cicatrization of the soft parts, we find they differ greatly, if we admit the 
existence of granulations. But these pretended granulations are only iHusory 
We can easily demonstrate the identity of the process of nature, to unite all the 
«Sw! ^ ? -^ dW1 r *£■ °? e diflrer ence seemingly offered by callus, compared 
With the cicatrization of the soft parts, is the development of a substance, which 
exists only lor a time, and which is formed externally to the fragments, in the 
medullary cavity This substance is, perhaps, much more marked in the bones 
only because it is formed by a firmer and consequently by a more perceptible sub- 
stance, or because it remains a longer time, and its quantity is in relation to the 
resistance it must present to give the bones all their force and all their solidity 
VYernaysay also, that the duration of its existence depends on the trifling degree of 
vitality of the bones, and on the slowness with which it is re-absorbed, or on its treat 
utility. In fact, it serves not only to cicatrization, but also opposes the displacement 
of the parts ; it maintains their relations, and lessens, in some measure, the disadvan- 
tages resulting from a want of contact or correspondence between the ends of the 
fragments. If wc could observe fractures when the relations of their fragments were 
unchanged, and the ends of the bones were unmoved, and these bones were pro- 
vided with a power of vitality similar to that of the soft parts, we should probably 
see in the formation and arrangement of the callus, a perfect similarity with the 
cicatrization of the other tissues. The practical consequences to be drawn from 
these experimental researches on callus, arc, that the union of the fracture is not 
real, till the definitive callus is formed, and that then the organ can fulfill its func- 
tions without danger of unnatural curves. The provisional callus situated princi- 
pally between the bone and periosteum, is only to retain t he parts together, to favor the 
formation of the definitive callus. The first callus once formed, alfapparatus may be 
removed ; but immobility is necessary, and when the second callus is completed the 
organ has regained its firmness, and can fulfill all its functions. In the treatment of 
fractures, then, two periods exist : in the first, wc employ means to reduce it and to 
hold the fractured parts together; in the second, the affected parts remain at rest 
and the dressings of the fractures are removed ; it coincides with the definitive 
callus. p T. 

(1) H. Park, Account of a new method of treating diseases of the joints of the knee 
and elbow, London, 1783. — Cases of the excision of carious joints, by H. Park and 
P. F. Moreau,with observations by J. Jefray, Glasgow, 1806.— Wachter, Diss, de 
articul. e.rtirp., Groningcn, 1810.— Morcau, De la resection des os, Paris, 1816.— 
Roux, De la resection, <ies os, Paris, 1822. 



228 GENERAL AN ATOM V. 

When the conditions are perfectly normal, the subject is in good 
health, and the fragments of the broken bone are placed in contact, 
the osseous substance is never produced in excess. If a portion of bone 
has been entirely removed, as in amputation,(l) the extremity of the 
stump becomes round, shrinks a little, and covers itself with a compact 
substance more or less dense. The fractures and injuries of the bones, 
however, are not always cured so completely, nor do we always 
see bones which have been destroyed to a greater or less extent by 
any cause whatever, completely regenerated. The causes of this differ- 
ence are dynamical or mechanical. To the first class belong, 1st, age ; 
2d, general weakness; 3d, diseases which affect the bones, as the scurvy 
and rickets, especially the former ; 4th, the concentration of the forma- 
tive power in some other organ, which prevents the union of a frac- 
ture^) during pregnancy, and the period of lactation, although it does 
not always operate. (3) The same causes, especially the first, dispose the 
callus to soften, particularly when the fracture has not been long united. 

The second class of causes comprises all that prevent the pieces 
of bone from touching, as an absolute defect in fitting them, and the 
continual derangement of the fracture by the motions of the part. 
Hence the reason that fractures of the ribs and patella are not often 
perfectly healed. 

In these cases an artificial joint (articulus abnormis s. artijicialis,) 
is formed, and the limb is useless, at least in some measure, since it 
is deficient in firmness. 

The state of the parts is not always the same in the artificial 
joints. (4) 

Sometimes the fragments adhere by means of a ligamentous or car- 
tilaginous mass. (5) Sometimes they remain separate, and are con- 
nected like the moveable joints, by a capsular tissue. (6) Finally, some- 
times muscular or tendinous fibres are formed between them. The 
first state resembles the symphyses, and the second the synovial joints. 

(1) P. G. Van Hoorn, Diss, de its, quae in partibus membri, prazscrtim osseis, am- 
putatione vulneratis, notanda sunt, Leyden, 1803, p. 36-129. — Brachet, Memoire de 
phys. pathol. sur ce que de vient le fragment de Vos, apres une amputation ; in the 
Bulletin de la soc. med. d 'emulation, Paris, 1822. 

(2) Alanson, in the Med. obs. and inq. vol. iv, p. 414. 

(3) Fab. Hildan, Obs. chcr. cent. v. obs. 87 ; cent. vi. obs. 68. — Hertod, in the Eph. 
A. C. D. 1. no. 1, obs. 25. — Schurig, Syllcpsiologia, 1731, p. 517. — Alanson, Med. 
obs. and inq., vol. iv, n. 37. 

(4) Wardrop, Case where a seton was introduced, etc. ; in the Med. chir. tr. vol. 
v. p. 367. — Salzmann, De attic, analogis qua fracturis ossium superreniunt, Stras- 
bourg 1 , 1718. — H Kuhnholz, Considerations sur les fausses a.rticidations, in the 
Journ. compl., vol. iii, p. 289. 

(5) Van Dceveren, Spec, obs'.'acad., p. 204. — Walter, Anafom. Museum, vol. ii. no. 
650-656. — Morand, Descript. du cab. du roi, in Buffon, Hist, nat.gen., vol. iii. p.. 
76. pi. i. — Cooper, in the Med. records and researches, vol. i. — Bonn, Thes. oss. morb, 
clxx, clxxxiii, clxxxiv. — Langenbeck, On the formation of false articulations 
consequent to fractures ; in the Ncue. Bibl.fiir Chirurgie, Gottinjren, 1815. cah. i. p. 
94, 95. 

(6) Koehler, Bcschreib. von Loder % s Prccparaten, p. 66-- 105. — Walter, loc. cit. n. 
651, 652, 653, 654, 656, 657.— Home, Trans, of a soc. for the impr. of med. and 
surg. knowl. vol. i. p. 233. 



OF THE OS8EOU3 SYSTEM IN THE ABNORMAL STATE. 229 

In the latter case the .extremities of the bone are rounded, smooth, 
and here and there are cartilaginous. Usually, one is excavated, and 
the other is elevated, so that they represent, the first the cavity of a 
joint, and the other its articulating head. 

The extremities of the bones are sometimes swelled, but usually 
this is not the case. The capsule of the joint secretes synovial fluid. 
Sometimes cartilages and unnatural bones form in these false joints, 
similar to those not unusual in the natural joints.(l) 

When dynamical causes oppose the formation of callus, it is formed 
when they cease to act, although its formation may be very slow ; 
for instance it may continue during the whole period of pregnancy. 
When the obstacles are mechanical, the ends of the bones are almost 
always cicatrized, and the cure takes place by the efforts of nature 
alone. The formation of callus, however, may be stimulated by pro- 
per means, which are not the same in all circumstances, but all of which 
tend to the same end, that of changing the cicatrized surfaces into a 
recent wound, and of stimulating the vitality of the bone locally. (2) 

These phenomena are seen not only in fractures of a single bone, 
(3) but even in those of two adjusted to each other.(4) 

§ 248. The power of reproduction in the bones develops itself with 
more energy, when an entirely new bone is formed in the place of an 
old one, which by some means has become dead. It is not the re- 
production of the bone, but its death, which constitutes the essence of 
the disease necrosis ; for, the regeneration is always accidental, and is 
never a disease, although it almost always a'ttends the death of bone. 

This power is seen particularly in the cylindrical bones, which pos- 
sess it in the highest degree. (5) 

The principal conditions of their reproduction are as follows : 

When a part of a bone is dead, which does not necessarily imply a 

(1) Home, loc. cil., has given the best description of an artificial capsular joint of 
thi3 kind. 

(2) White, Cases in surgery, London, 1770, p. 69-93. — Inglis, Obs. on the cure of 
those unnatural articulations which are sometimes the consequences of fractures in 
the extremities ; in the Edinb. Med. Journ., vol. i. p. 419. — Rowlands, A case of an 
un-united fracture of the thigh cured by saving off the ends of the bone ; in the Med. 
chir. tr. vol. ii. n. v. — We find an excellent account of the different modes with se- 
veral interesting- cases in Wardrop's Memoir mentioned above. — Delpech, art. Cal, 
in the Diet. des. sc. med., vol. iii.p. 451--453. 

(3) As Boyer thinks, Lecons sur les les malad. des os vol. i. p. 69. 

(4) White, loc.cit., p. 79. — Wardrop. Inglis. 

(5) The principal works on this interesting- subject are, Chopart, Denecros. ossium 
theses anat. chir., Paris, 1776. — Louis, Sur la necrose de I'os maxill. inf. ; in the Mem. 
de chir. de Paris, 1772, p. 355, Paris, 1782. — Troja, De novorum ossium inintegris 
aut maximis, ob morbos, deperditionibus, regeneratione experimenta, Paris, 1775. — 
David, Observ. sur une maladie connue sous le nam de necrose. — Weidmann, De ne- 
crosi ossium, Erfort, 1793. — Russell, Practical essay on a certain disease of the bones 
called necrosis, Edinburg-h, 1794.— Koeler, Experimenta circa regenerationem ossium, 
Gottingen, 1786.— Macdonald, De necrosi et callo, Edinburgh, 1799.— Macdonald, 
in Crowthcr, Pract. obs. on the diseases of the joints, London, 1808. — Macartney, in 
Crowther, Practical observations on the diseases of the joints, London, 1808. — Char- 
meil, De la regeneration desos, Metz, 1821.— Knox", in the Edin. med. and sur g. jour- 
nal, 1822, and 1823. 



230 GENERAL ANATOMY. 

great change in its form, color,(l) or chemical composition, (2) it is de- 
tached from the healthy portion, because nutrition does not extend be- 
yond the limit which separates it, and absorption acts more rapidly 
upon it. 

But at the same time the formation of a new bone commences. It 
results from a considerable development of the vessels of the periosteum, 
and of the adjacent cellular tissue, which also becomes softer. As the 
bone dies, a gelatinous fluid is effused in all the surface between it and the 
periosteum. This fluid gradually thickens, and is changed into real 
osseous substance. It first becomes cartilaginous, and afterwards, but 
rarely in less than twenty-four days after the commencement of the 
disease, points of bone are seen in the cartilage. The new bone finally 
unites and fuses with the healthy parts of the old bone. 

As the progress of these two actions, the mortification and the detach- 
ment of the old portion of the bone, and the formation of the new 
bone, and its union with the sound extremity of the old bone is nearly 
equal, the patient does not generally lose the use of his limb, although 
it often happens that the body of the old bone is entirely detached. 
But it is sometimes lost, because the dead bone detaches itself before the 
new bone has time to unite with the healthy portions. Besides, since 
when the old bone dies it detaches itself from the periosteum, and as 
the new bone forms below this " membrane which is iisually uninjured, 
to which it unites by the anastomoses of their respective vessels, and 
as the tendons are inserted in the periosteum^ it is natural that these 
latter, when detached from the old bone, should be inserted in the new, 
as is usually the case. 

Even when the periosteum dies, these essential conditions are not 
changed, for it is replaced by a new periosteum, formed from the sur- 
rounding cellular tissue. 

The newly formed bone perfectly resembles the old one in several 
respects : it also differs in some. 

Its hardness, length, and connections with the neighboring parts are 
the same ; but its form and thickness differ. It is generally larger, 
because it surrounds the old bone, around which it forms. It is more 
or less shapeless and massive, and its fibres are not so regular. Its sur- 
face is very uneven and very rough, because not included in the primi- 
tive plan of the organization. It has then, like allaccidental ossifications, 
a form less distinctly marked, and which would be even less so if the 
ancient bone did not serve as a model. The thickness of the new bone 
is sometimes very considerable. It often exceeds an inch in the large 
bones, as the humerus and femur. Usually it is increased in this man- 
ner; when the the dead portion is thrown off from within the new 
bone, in one of the ways we shall mention directly, the cavity of the 
latter is almost always obliterated, by the increase which continues 
within, so that no regular medullary canal remains, and the new bone 
is entirely solid. (3) 

(1) Weidmann, Denecrosi ossium, p. 19. 

(2) Davy, in Monro, Outlines of the anatomy of the human body, vol. L p. 39. 

(3) Russell, 60-63. 



OP THE OSSEOUS SYSTEM IN THE ABNORMAL STATE. 231 

Although this is common, it does not always take place ; for some- 
times a regular medullary canal is found, extending the whole length 
of the bone, but possibly this is formed afterward. (1) 

The old dead bone seldom, in fact never, remains in the cavity of the 
new bone. (2) Sometimes it gradually disappears ; sometimes ft comes 
out of itself, either in one portion, or in different pieces, or it is removed 
by art. It passes off through several smooth, round openings, which 
penetrate entirely through the new bone into its cavity, and communi- 
cate with the skin by fistulous openings, which do not close till after 
the sequestrum is thrown off, being continued by its irritation, as a 
foreign body. 

We must remark, that the commencement of the openings appears 
when the new bone is first formed, for we can perceive in the gelatin 
which is effused, dry and opaque points, which soon change into 
them. 

The death and reproduction of a cylindrical bone rarely extend be- 
yondits body, and its spungy extremities remain unaffected, although the 
whole body perishes. This phenomenon is seen not only in youth, 
when the body and the extremeties form separate and distinct bones, 
but also in the advanced periods of life, at least very often. 

The bone never perishes in its whole thickness : often and from the 
nature of the causes, only its internal or its external portion decays. The 
first case may be confounded with the mortificatoin of the whole bone, 
because then it usually happens that the remaining part swells also, 
and openings are established for the separation of the dead portion. 
Still it may be distinguished, not only because the exfoliation is almost 
always smaller in every respect, but because the outer surface is very 
rough, while in a bone which has decayed in all its extent, this surface 
is very smeoth. 

The flat bones not unusually die ; but they are not generally, or 
but very imperfectly, reproduced. If they grow anew, the progress of 
nature is essentially the same. But the new bone does not surround 
the old one, as in the cylindrical bones, and it is in fact formed by the 
growth of the edge, which has preserved fife. The short bones also 
rarely die, and are as rarely regenerated. 

§ 249. The deviations of formation of the bones, which are de- 
veloped at all periods of life, are in regard to their mass and volume. 
They result in the unnatural enlargement or diminution of these 
organs. 

The bones are, perhaps, of all organs, the most subject to an unnat- 
ural enlargement. Sometimes they increase in all their circumference, 
which constitutes hyperostosis. Sometimes only a tumor is developed 
in some part of their extent ; this is called exostosis. Then their struc- 
ture is normal, or it is altered : the latter is most common. The bone, 

(1) Russell, loc. cit. in the appendix, case 1st. 

(2) Voigtel says, {Pathol, anat. vol. i, p. 195) that " the new bone is seldom hol- 
low, covering- the remains of the old bone, which are loose within it, as in a tunnel ;" 
but in all the cases he reports, the cure was not perfect, as the openings of the new 
bone were not closed. 



232 GENERAL ANATOMY. 

when altered, is sometimes looser and more spungy ; sometimes harder, 
more solid and heavier than usual. Swelling of the bones, with diminu- 
tion in density, is called spina ventosa. (I) Swelled bones are at first 
more spungy ; but when cured, they become harder and more solid. 
Osteosteatoma, or exostosis steatomides, resembles exostosis, and probably 
often, if not always, is an imperfect swelling of the bone, with a 
change in its chemical composition. (2) 

The bone rarely diminishes in size, unless the other organs are simi- 
larly changed, as when the process of nutrition is deranged from para- 
lysis. A change in their mass is observed less rarely, and this state is 
almost always accompanied with a change in their chemical composition. 

§ 250. The diseases of the last kind, which cause anomalies by a 
spontaneous alteration in nutrition,. lead so much more naturally to 
alterations in texture and chemical composition, that their influence is 
rarely exerted on the form alone. On the other hand, the form appears 
more or less changed in the anomalies of the bones, where the preva- 
lent character consists in a change in texture and chemical composition. 
The principal changes in the texture of the bones are as follows : 

1st. Inflammation, and its consequences, which differ from those seen 
in other organs, by their slow progress. Thickening, often also exos- 
tosis, especially the swelling of the bones, attended with diminution in 
their density, (spina ventosa) are manifestly the results of inflamma- 
tion, terminated by exudation. Suppuration is called caries, and mor- 
tification, necrosis. The principal phenomena of this last have already 
been mentioned. (§ 248.) 

2d. Diminution of hardness and solidity, of which there are different 
degrees. In rachitis, this exists in the slightest degree : the bones are 
soft, spungy, flexible, and curved, either in the places where they are 
acted on by muscles, whose power they cannot resist, t>r in those 
where they sustain some weight. At the same time they receive more 
blood. The periosteum undergoes analogous changes. The che- 
mical composition is not every where the same. In fact, we do not al- 
ways find the same relations between the respective proportions of phos- 
phoric acid and lime, as sometimes there is too much, (3) and sometimes 
too little(4) acid; and again, the proportion between the animal sub- 
stance and the earthy portion varies much. Sometimes the quantity of 
animal matter is much enlarged, so that its relations are as 74.26 . and 
even as 75.8 : 24.2 :(5) or finally as 79.54 : 20.5.(6) Sometimes it does 
not differ from what is found in the normal state, and is even less, being 
as 25.5 : 74.5 :(7) although the bones are spungy. These differences 

(1) Augustin, De spina ventosa ossium, Halle, 1797. 

(2) Hundertmark, Ostcostcatomatis casus rarior, Leipsick, 1757. — Herrmann, De 
osteatomate, Leipsick, 1767. 

(3) Jager, Diss. acid, phosph. tanquam morb. quorumd, causs. prop., Stuttgardt. 
1793. 

.(4) Ackermann, Comment, rued, de rachitide, Utrecht, 1794. 

(5) Davy, loc. cit. p. 38. 

(6) Bostock, in the Med. and chir. trans, of London, vol. iv, p. 38. 

(7) Davy, loc. cit. p. 39. 



OF THE OSSEOUS SYSTEM IN TUE ABNORMAL STATE. 233 

are probably owing to the degree, and especially to the period, of dis- 
ease ; but they at least prove that rachitis does not essentially consist 
in a deficiency of earthy matter. This disease is seen in children par- 
ticularly. In rachitis the bones are generally, proportionally speak- 
ing, too short and too thick : the head is larger, and the points of 
ossification of the bones of the skull are very distinct. 

In softening of the bones (osteomalacia, osteosarcosis) this state ex- 
ists in a higher degree. The bones then become still softer, fleshy, or 
lardaceous, so that they may be easily cut. Their cellular structure 
disappears, and they become a homogeneous substance. At the same 
time they are more or less swelled. They present curves which are 
greater in proportion as the bone is softer, This is more frequent in 
females. The teeth are usually but not always free from it.(l) The 
results are deformity and crookedness of the extremities, or of the 
whole body, according as the disease of the bones is partial or gene- 
ral, and according as the bones yield to the efforts of the muscles, and 
to the weight of the whole body. 

A state resembling this is the excessive brittleness of the bones, 
although it sometimes arises from an excess of earthy matter. 
This fragility is often so extensive, that the bones break from the least 
exertion, as from turning in bed, &c. It not unfrequently attends the 
softening of the bones, but it is usually found alone. The diseased 
bones do not lose their cellular structure, as in osteosarcosis, but it 
often becomes more distinctly marked. The principal causes of this 
state of the bones are general diseases which are of long duration, 
which affect to a greater or less extent all the systems, as scurvy, 
cancer, and syphilis. 



II. OF THE ARTICULATIONS OF THE BONES. 

§ 251. The joints vary from the normal state in two ways. The 
corresponding ends of the bones may be too loosely or too firmly united 
with each other. 

§ 252. The too slight union of the bones may result from rupture or 
forcible extension, or from the relaxation of the means of union. These 
different states give rise to luxation, (luxatio,) which consists essen- 
tially in the separation of the movable extremities of the bones united 
together, and in the contact of a movable with an immovable bone in, 
a place which is not normal, towards which it has been drawn by the 
muscles placed near the joint. Luxation takes place more easily, 
and consequently is more frequent, as the motions of the bones are more 
extensive ; and it is usually attended with distension of the ligaments 
when it happens to the movable articulations, but they are broken 
if the joints are less movable. 

It always occurs naturally in the direction where the resistance of the 
articulating surfaces, the ligaments, and the adjacent parts, is the least. 
(1) J. S. Plank, De osteosarcosi commentatio, Tubingen, 1782. 

Vol. I. 30 



234 GENERAL ANATOMY. 

When the bone does not resume its natural place, either by itself or 
the assistance of art, a new joint is formed, and the old one disappears. 
The bone with which the dislocated bone comes in contact usually 
forms a superficial hollow, which is covered first with periosteum, and 
afterward partially or wholly with cartilage, the edge of which is more 
or less turned over. At the same time the articulating head becomes 
flatter and more unequal than before, and often partially or wholly 
loses its cartilage, being pressed against the other bone by the mus- 
cles. 

Sometimes a cavity is formed in the bone which was provided with 
an articulating head, to which corresponds a proportional head which 
grows on the surface of the other bone. 

The immovable articulations are sometimes dislocated, or are less 
firm from an original deviation of formation. 

The latter is seen in hydrocephalus, and when the bones of the 
pubis are not joined. The former, if we except the symphysis pubis 
at the end of pregnancy, arises only from mechanical violence, the 
action of which is sudden and strong, or slow and gradually increasing. 

In congenital and normal separation, the uniting medium is dis- 
tended or lengthened ; it is ruptured when they are separated ac- 
cidentally. 

§ 253. An unnatural solidity in the joints constitutes anchylosis : (1) 
this is false (A. spuria) when the means of union are only contracted 
or too stiff, and true {A. vera) when the bones which were sepa- 
rated in the healthy state are joined together by osseous matter. The 
consequence of anchylosis is the immobility of parts once movable. 

In this case, either the fibrous ligaments are ossified, or osseous sub- 
stance is deposited below them, and unites the surfaces of the two 
bones like a bridge, or the two bones are fused together in the 
whole extent of their corresponding surfaces, so that the cartilage 
which incrusts them and the compact substance disappear, and 
we find only a spungy substance, uniformly extending the whole 
length of the bone. The first two forms are found naturally in old 
age. The last is seen after inflammation and suppuration of the ends 
of the bones. 

Sometimes, without any known cause, a tendency to ossification 
shows itself in several, and even in all the joints ; which is attended 
with stiffness of the whole body. 

ARTICLE THIRD. 

OF ACCIDENTAL OSSIFICATION. 

§ 254. The accidental development of bone is a very frequent phe- 
nomenon,^) and is seen principally in certain systems, but is not ge- 

(1} J. T. van de YVynpersse, De ancylosi, Leyden, 1783. 

(2) J. van Heckeren, De osteogenesi prcEternaturali, Leyden, 1797. 



OF ACCIDENTAL OSSIFICATION. 235 

nerally manifested till the latter periods of life. It appears especially in 
the left side of the heart, and in the system of the aorta, particularly its 
inner membrane (p. 151). It is not much more unfrequent in the 
serous membranes. It is seen less frequently in the fibrous organs, 
among which the periosteum furnishes the most examples. Acci- 
dental bones often form also in the internal genital organs, especially 
the uterus, in some fibrous bodies, in the thyroid gland, and in the ovaries. 

Accidental ossifications present themselves under two different forms. 
Sometimes the osseous substance forms a connected whole with the 
parts in the midst of which it is developed, a part of the substance in 
which the bone forms, is changed into it. Sometimes it forms a sepa- 
rate body, a new formation, which is connected with the part in which it 
is rooted only by the relation of nutrition, and sooner or later is insulated 
when this relation ceases. 

Accidental ossifications of the first kind are developed principally in 
the vascular system, and in several parts of the serous system. The 
second species is usually seen in the synovial capsules, and in the 
natural and the accidental mucous bursas ; and also in several serous 
membranes, especially the tunica vaginalis testis. 

The latter forms more or less extensive layers which project but 
little or not at all above the surface of the parts in which they are 
developed. The former have the form of round bodies with peduncles, 
and are developed most frequently in those joints exposed to frequent 
concussions : they are sometimes single, sometimes very numerous, and 
always communicate at one time or another with the synovial mem- 
brane. 

Finally, these accidental osseous productions pass through the same 
periods as the normal bones.(l) 

(1) Broussais, in his Histoire des phlegmas. chron., Paris, 1808, vol. i., attributes 
these accidental substances, both osseous and calcareous, to a chronic inflammation 
of the lymphatics. This opinion was revived by him in 1816, in his Examen. 
Boisseau,admitting inflammation as the most common cause of accidental ossification, 
thinks that it occurs only when inflammation is followed by a diminution in nutrition, 
and that we cannot admit the continuance of the inflammatory state in atissue which 
is accidentally ossified. (Reflexions sur la nouvelle doctrine medicate, in the Journ. 
univers. des sc. med., vol. vii., 1817, p. 43.) In answer, Broussais distinguishes two 
kinds of accidental ossifications : 1st, the inorganic osseous concretions, the secon- 
dary results of a low degree of irritation, which form in the extravasated lymphatic 
fluids, or in tissues partly disposed to vital inflammation ; 2ndly, the pure and sim- 
ple ossifications without previous alteration of the organization, consisting in those 
anomalies of nutrition consequent upon the progress of age. (Journ.univ.des sc.medic, 
vol. viii., p. 156.) Gimelle afterward established that these accidental osseous sub- 
stances never have the form nor the structure of the primitive bones, and that acci- 
dental ossification is always the result of a chronic inflammation, which, using the 
vital properties of an organ to exalt them above their natural type, changes the 
intimate nature of the affected part, and communicates to it the power of incrusting 
itself with phosphate of lime. (Me'moire sur les ossifications morbides, in the Journ, 
univ. des sc. mid., vol. xviii., 1820, p. 5.) Rayer has since advocated the opinion that 
morbid ossification is always the result of an inflammatory process. He divides it, 
1st, into that which occurs in a tissue of the primary formation, where the form and 
structure are not changed, so that it cannot be mistaken ; 2d, into that develpeod 
in an accidental tissue which has experienced no change ; and 3d, into that which 
supervenes in a primitive or accidental tissue, which has been changed most fre- 



236 GENERAL ANATOMY. 

SECTION V. 

OP THE CARTILAGINOUS SYSTEM. 
ARTICLE FIRST. 

OF THE CARTILAGES IN THE NORMAL STATE. 

§ 255. The cartilages (cartilago)(l) are solid, hard, smooth, slip- 
pery, very elastic, whitish, and apparently homogeneous bodies, pos- 
sessing neither fibres nor laminae. 

§ 256. They form an organic system, which does not exert the same 
influence in the organism at all periods of life, since in the early periods, 
we find them in the places of the bones, but they gradually disappear. 
Hence the cartilages are divided into the permanent ( C. permanentes) 
and the temporary, (C. temporarice,) a distinction which is not exact, as 
many cartilages which are included in the first series, become bone in 
most subjects, although in fact much later than the others, and always 
incompletely. The term temporary cartilage is usually applied to 
those only which are replaced by bones, and which thus disappear 
completely at about the same period in all individuals. When the 
temporary cartilages are changed into bone, the permanent cartilages 
are found principally, 1st, at the ends of those bones which touch 
each other, whether movably or immovably articulated ; 2d, in the 
parietes of certain canals. 

We can make no general remarks in regard to the forms of the 
temporary cartilages, as they assume those of the bones, which after- 
wards take their places. But the permanent cartilages, except the 
arytenoid and those small ones found between the thyroid cartilage and 
the hyoid bone, are very thin in proportion to their breadth and length, 
or at least in respect to one of these dimensions. 

quently into a fibrous or a cartilaginous substance. (Memoire sur I' ossification 
morbide consider ee comme une terminaison des phlcgmasies, in the Archives gene- 
rales de Medicine, vol. i., 1823, p. 313 and 489.) Hence we may judge that the 
history of abnormal ossifications is still very obscure. This name very probably 
comprises numerous accidental productions, which should be considered only as 
calculous concretions. In order that an abnormal formation should justly come 
within the osseous system, it must possess life, that is, it must be attached at least 
by vessels to the rest of the organism, and its structure must perfectly resemble that 
of the normal bones. But these two conditions are found, perhaps, only in the forma- 
tion of callus, the regeneration of the bodies of the long bones, and the ossification 
of certain parts of the fibrous tissue. F. T. 

(1) G. Hunter, Of the structure and diseases of articulating cartilages, in the 
Phil, trans, n. 470, vi., p. 514-521. — Hcrissant, Sur la structure des cartilages des 
cotes de I'homme et du cheval, in the Mem. de Paris, 1748 ; p. 355. — Delassone, Sur 
V organisation des os, in the Mem. de Paris, 1752, p. 253-258. — J. G. Haase, De 
fabrica, cartilaginum, Leipsic, 1767. — C. F. Doorner, De gravioribus quibusdam 
cartilaginum mutationibus, Tubingen, 1798. — B. C. Brodie, Pathological researches 
respecting the diseases of the joints, in the Med. chir. tr.,\o\. iv., no. xiii., § 5. — Lacnnec, 
Sur les cartilages accidentels, in the Diet, des sc. mid., vol. iv., p. 123-133. 



OF THE CARTILAGINOUS SYSTEM IN THE NORMAL STATE. 237 

§257. The outer surface of the cartilages situated on the ends of 
the bones is somenmes unattached; they are then called articular 
cartilages, (C. articulares.) Sometimes these cartilages form a layer, 
the two faces of which are united with the bones. They are then 
called the cartilages of the sutures, ( C. suturarum. ) 

§ 258. The articular cartilages are found in all the movable ioints • 
they line the corresponding extremities of the bones, imitating their 
forms perfectly, and are united with them so closely, that one can 
break the bone sooner than separate them. The cartilage which 
exists at first in the place of bone, is perfectly homogeneous, yet 
when the latter is entirely developed, the articular cartilage is not a pro- 
longation of it, since there is no continuity of tissue between them 
even after the gelatin and the earthy salts have been liberated from 
the bones by acids. The loose surface of these cartilages is smooth 
because it is connected with the internal layer of the articular mem- 
brane. Ihis arrangement diminishes remarkably the friction conse- 
quent upon motion. 

The articular cartilages are generally a little thinner on their cir- 
cumference ; this is particularly seen in those attached to the extremi- 
ties of the bones which project very much, as the heads of the hu- 
merus and femur. On the contrary, the articular cartilages of the 
cavmes which receive these heads are thickest on their edges, and are 
often strengthened m that part by a cartilaginous band. The carti- 
lage has a uniform thickness in all other points of its surface. 

§ 259. The second kind of the cartilages which are placed between 
the bones, form a simple, very thin band, situated between two 
adjacent bones, which they unite to each other so as not to permit 
the least motion. These cartilages have usually a conical shape, and 
are broader on their external than on their internal face. This ar- 
rangement explains, at least in part, why the sutures of the bones 
of the head, in which the cartilages we speak of are found, always 
disappear on the inner sooner than on the outer face of the skull. 

The costal cartilages form in some measure an intermediate section 
between these cartilages and those of the second class; for their posterior 
extremities are connected with the ribs, like the artioular cartilages 
while their anterior ends articulate with the sternum, which is itself 
covered with an incrustation of cartilage. Some are even united to 
this bone by an articular capsule also. Besides, they differ from all 
the others, because their length much exceeds their breadth and thick- 



ness 



§ 260. The cartilages of the second class'are much more independent 
than those of the first, for they constitute the base of certain organs 
which are almost entirely formed by them. Thus the larynx is chiefly 
composed of cartilages, and the form of the trachea depends principally 
on that of the cartilaginous rings which form its parietes. The same 
may be said of the cartilages of the nose and the ear. Hence the forms 
of these cartilages differ more than those of the preceding. In fact they 
form sometimes layers, sometimes rings, and sometimes thick masses. 



238 GENERAL ANATOMY 

They vary also in tissue ; some, as those of the larynx, the trachea, 
and the septum of the nose, are much harder than those of the alee of 
the nose, of the ear, and of the eyelids. They are generally more flex- 
ible than the cartilages which are connected with the bones. Many 
of them, which articulate together so as to admit motion, as for instance 
in the larynx, present articular processes lined with capsular liga- 
ments and retained in place by fibrous layers which are continuous 
with the perichondrium : but most of them are united only by this mem- 
brane, by mucous tissue, and the membranous expansions which extend 
from one to another. 

§ 261. Although at first view the cartilages do not seem to 
have an organic tissue, (§ 255,) nevertheless, by having recourse to 
different processes, such as continued maceration and the action of 
acids, we can demonstrate more or less clearly, that they are formed of 
fibres and of layers. This tissue is slightly flexible, so that it breaks 
if we endeavor to bend it. The cartilage putrifies with difficulty: 
it is one of those substances which resists decomposition the longest. 

All the cartilages, however, have not the same tissue ; among 
those which are attached to the bones, the articular cartilages are 
formed of a multitude of short fibres, which are implanted in the cir- 
cumference of the bones, and become softer towards their unattached 
extremity. The costal cartilages are composed of oval lamina, ad- 
justed to each other from within outward, and kept in place by 
the transverse fibres. Morgagni(l) pretends that the cartilages of the 
larynx, or at least the cricoid and arytenoid cartilages, often have a 
cellular structure, and inclose marrow, even although they are not 
ossified. We have never observed any thing like this. 

§ 262. The chemical composition of the cartilages resembles that of 
bone : they are formed of an animal substance and of phosphate of 
lime ; but the proportions of these two principal constituents, perhaps 
also the nature of the animal material, are different. In fact, from the 
latest researches of Davy,(2) the articular cartilages contain, 

Of albumen, 44.5 

" water, - 55. 

" phosphate of lime, 0.5 

According to Allen,(3) on the contrary, the animal matter is also of 
a gelatinous nature, and the earthy material, mostly a carbonate of lime 
forms only one hundredth part of the whole mass. Hatchett says, 
they are formed of coagulated albumen, containing some traces of 
phosphate of lime. 

§ 263. The cartilages have no vessels which carry red blood, al- 
though in cutting them we often perceive vessels distinct from their 
substance. Lymphatics have not as yet been discovered in them. 
They are destitute of nerves. 

§ 264. All the cartilages, if we except the articular, are enveloped 
with a fibrous membrane called the perichondrium. This membrane 

(1) Advers. anat., i., an. 23. 

(2) In Monro, Outlines of anatomy, vol. i., p. 68. 

(3) Macdonald, De necrosi etcallo, Edinburgh, 1799, p. 104, 105. 



OF THB CARTILAGINOUS SYSTEM IN THE NORMAL STATE. 239 

is connected with them in a mechanical or dynamical relation, less in- 
timately than the periosteum is with the bones. The articular carti- 
lages are destitute of this perichondrium, and their unattached face i3 
blended with the synovial membrane. 

§ 265. The cartilages are very elastic : hence they are found in 
those places where this property is required ; for instance, in the ends 
of the long bones, in the parietes of those cavities which change their 
size and which should never collapse, as the nose, the organs of voice 
and of respiration. They possess, however, but a slight degree of 
contractility and dilatabihty. Their want of nerves explains their 
entire insensibility in the normal state. The phenomena of life pro- 
gress in them with extreme slowness. 

§ 266. During the early periods of existence the cartilages are 
mucous and soft. They gradually become consistent, and are finally 
very brittle. Towards the middle of fife they are more elastic, because 
then they are more distant from the two opposite states in which they 
are met with at the beginning and end of existence. 

As certain cartilages, those called temporary, ossify regularly and very 
early, so too some of the permanent cartilages are totally or partially 
changed into osseous pieces : at least this happens very often in regard 
to some of them ; but they generally ossify much later than the others. 
Those which present this phenomenon most frequently are the carti- 
lages of the larynx, and less frequently those of the ribs, and the rings 
of the trachea. It is never seen in those of the nose, the ears, or the 
eyelids. This change is very rare in the articular cartilages. Still 
we must mention here those uncommon cases where all the joints are 
fused in a greater or less degree at an advanced age, and where, con- 
sequently, all the articular cartilages are ossified. Between the per- 
manent and the temporary cartilages, we may rank to a certain extent 
those which unite two bones together in such a manner as not to 
allow motion, for they also change into osseous substance, and hence 
the sutures disappear, although the change occurs almost always long 
after that of the temporary cartilages. The form of the connected 
surfaces of the bones appears to influence this change to a certain 
extent, although it occurs where the points of contact are more nu- 
merous and closer, as in the dentated sutures, or within the skull, sooner 
than between smooth faces, as around the unguiform bones, between 
the upper maxillary bones, &c. But this law is evidently obedient to 
other laws also : for on one side the two portions of the lower jaw, 
whose surfaces touch in the same manner as those of the upper jaw, 
always unite early ; so on the other side, we often see superficial su- 
tures, as the squamous, disappear, while others which are very deep 
and supplied with numerous indentations are permanent. 

The proportional size of the cartilages remains abou t the same at all 
periods of life : those of the sutures are the only exceptions to this rule. 
In fact, during the early periods of existence, while the bones of the 
head play on each other, and while their teeth are not inserted into each 
other, these cartilages are broader than they are afterwards. 



240 GENERAL ANATOMY. 

ARTICLE SECOND. 

OF THE CARTILAGINOUS SYSTEM IN THE ABNORMAL STATE. 

§ 267. The cartilages rarely present anomalies(l) in regard to their 
external or internal form : their deviations of formation are rarely con- 
genital and usually result from anomalies presented by the bones and 
ligaments. 

We may consider as congenital deviations of formation the defi- 
ciency of certain cartilages, for instance those of the ribs. 

§ 268. The slowness of the vital phenomena which marks the carti- 
lages generally (§ 265) is seen also in the manner of their action on ex- 
ternal morbific causes, and the degree of their power of repairing a 
loss of substance, their reproductive power. The wounds of the carti- 
lages do not heal, like those of other parts, by the union of their divided 
surfaces. Long after the accident, these surfaces present no change which 
indicates the least tendency to union : they are smooth and level ; 
but the parts which cover the cartilage, especially the perichondrium 
when it exists, adhere, and form the new substance which is deposited 
between the lips of the wound. Hence why it so often happens that a 
cartilage destroyed in any manner is never reproduced, although layers 
of cartilage are sometimes developed on the surfaces of the false arti- 
culations. But this last phenomenon is not common. Articular car- 
tilages are rarely or never formed in the new articular cavities which 
appear after luxations. In fact in the false joints consecutive to 
fractures, we sometimes find cartilages between the disunited ends of 
the bones, and farther the artificial joint is formed because they are not 
ossified : but, in this case, it is not a cartilage which is reproduced, nor 
even a permanent cartilage which forms, but only a temporary carti- 
lage, or rather a new bone, the development of which has been ar- 
rested. 

When the articular cartilages are destroyed, the most favorable 
occurrence is the fusion of the contiguous surfaces of the two bones, 
and the formation of anchylosis. 

For these reasons, inflammation of the cartilages is unfrequent, and 
very slow : they resist the action of deleterious causes longer even 
than the bones ; and the changes which occur in them seem to be pas- 
sive and chemical, rather than active and vital, since cartilages, when 
separated from the body and exposed to the same agents, are affected 
in the same manner. 

We shall not here discuss the opinion of Laennec, who admits that 
destroyed cartilages may be regenerated. We consider those thin 
points of articular cartilage usually .found in several articulations at 

(1) Doerner, De gravioribus quibusdam cartilaginuni mutationibus, Tubingen, 
1798. — Cruveilhier, Observations sur les cartilages diarthrodiaux et les maladies des 
articulations diarthrodiales, in the Archiv. gcner.de med., Feb. 1824, p. 161. 



OF THE CARTILAGINOUS SYSTEM IN THE ABNORMAL STATE. 241 

once in the same subject, as new productions of cartilage, as real cica- 
trices, which are never as thick as the old cartilage. ■ But it is not 
proved, that these thin points do not arise from a wasting of the carti- 
lage ; and the circumstances in which we have sometimes observed 
this phenomenon, render this last opinion not improbable. 

§ 269. Active changes also occur in the cartilages. These take 
place particularly in those which do not concur in forming the articula- 
tions, because they receive more vessels, and enjoy a more active exist- 
ence. In fact the cartilages not unfrequently inflame, and this in- 
flammation terminates in ossification. The articular cartilages rarely 
experience these alterations, but they are not always exempt from 
them : thus in diseases of the joints, they become red, partly lose their 
density, soften, and swell. Inflammation most generally terminates in 
suppuration and the destruction of the cartilages, which it is remark- 
able does not necessarily produce the formation of pus. It is probably 
from these changes that the wasting of the articular cartilages takes 
place. 

The cartilages are exposed to induration and ossification, anomalies 
of which we have spoken above, (§ 266.) When in this state they 
become subject to the usual diseases of the bones. They inflame, 
become carious, die, and are thrown off. This phenomenon occurs not 
unfrequently in some cartilages of the larynx, particularly in the aryte- 
noid cartilages. We must not confound this with the formation of a 
white substance, probably urate of soda, which develops itself in the 
place of the articular cartilages, when the latter disappear from the 
effects of gout 

§ 270. The cartilages not unfrequently develop themselves acci- 
dentally. In general, when this anomalous formation is seen, we may 
admit a tendency to accidental ossification. The solidity, form, and 
situation of these accidental cartilages vary much. They differ so 
much from each other in the first respect, that Laennec thought to 
make two classes, the perfect and the imperfect. But this classifica- 
tion hardly seems admissible ; for the difference is purely gradual and 
accidental, and every thing would induce us to think that it depends en- 
tirely upon the period when the observation is made. Farther, the acci- 
dental cartilages are presented under three principal forms : 

1st. As broad layers adhering more or less strongly by their two faces 
to the parts in which they are found. This form is the most common. Ac- 
cidental cartilages of this kind are developed principally between the in- 
ternal and the fibrous tunics of the arteries, generally on the external face 
of the internal membrane of the system of red blood, and on the outer 
face of the serous membranes, so that as this resembles very much the 
internal membrane of the vessels, the formation of the cartilaginous 
layers may be considered one of the most usual morbid alterations. 

2d. In the form of more or less round, irregular, and more or less 
solid masses, which are imbedded in the substance of the different 
organs, especially the uterus, the thyroid gland, and the ovaries. 

Vol. I. 31 



242 GENERAL ANATOMY 

3d, As rounded, ( flat, smooth concretions attached to fine filaments, 
and which are often separated from the parts whence they arise, so 
that they seem perfectly loose. This kind of accidental cartilage 
occurs particularly in the internal face of the synovial membranes. 
They are more rare in the serous membranes. It is the first degree of 
the formation of accidental articular bones. (§ 254.) 



SECTION VI. 

OF THE FIBRO-CARTILAGINOUS SYSTEM. 
ARTICLE FIRST. 

OF THE FIBRO-CARTILAGES IN THE NORMAL STATE. 

§ 271. By cartilages we usually understand all those hard sub>- 
stances found between the bones which cover their surfaces, and some 
other parts mentioned before, (§ 260.) But the substances placed be- 
tween the bones differ much from each other. Hence we early per- 
ceived the necessity of dividing the cartilages into several classes, ac- 
cording to their texture, or at least we did not forget to remark that all 
have not exactly the same texture. Haase divides them into three classes: 
1, the cartilages formed entirely of a. dense cellular tissue; 2, the liga- 
mentous cartilages, (C. ligamentosm) ; 3, the mixed cartilages, (C. 
mixta.) Bichat considers the second class as a distinct system, 
and he has given to it the name of fibro-cartilage — and has made 
three subdivisions of it, viz. 1. The membranous jibro-carlilages, as 
those of the nose, the ear, and the trachea. 2. The articular fibro- 
cartilages, comprehending the loose interarticular cartilages, and those 
which adhere intimately to the bones by their two faces, as those found 
between the vertebrae and the ossa pubis. 3. The fibro-cartilages of the 
tendinous sheaths, which cover the bones in those places where the 
tendons glide over them. But it is unquestionably more exact to refer 
the first division to the cartilages properly so called, as they have the 
same structure. We ought also to add to the two subdivisions a third, 
that of the annular fibro-cartilages, which Bichat has not mentioned. 

The best classification of the fibro-cartilages is one in respect to their 
form and situation, and which admits of their being divided into three 
classes : 1st. Those fibro-cartilages the two faces of which are either 
wholly or at least in a great part loose, and the edges of which are 
united to synovial capsules, the movable articular fibro-cartilages. 

2d. Those which have one of their faces loose, and adhere to the bone 
by the other. These are, a. long and grooved, as the fibro-cartilages 
of the tendinous sheaths ; and b. or circular, as those which border the 
edges of the joints, and which may be termed the annular fibro-carti- 
lages. 

3d. Those which have both faces entirely attached to the bones be- 
tween which they are placed. 



OF THE FIBROCARTILAGINOUS SYSTEM IN THE NORMAL STATE. 243 

§ 272. The intermediate fibro-cartilages are found principally in 
those joints which are exposed to frequent and extensive friction, as 
that of the knee, of the clavicle, and of the lower jaw. They divide the 
articulation more or less completely into two parts, because they are 
parallel to the two articular faces between which they are extended. 
They are united more or less distinctly by fibrous parts to the circum- 
ference of the capsule or to the articular cartilages. Still they always 
remain movable, so that they can change their situation in the dif- 
ferent motions of the joints ; hence they diminish compression and the 
concussion experienced by the articular cartilages in motion. They 
are usually circular and bi-concave, that is thicker at the circumference 
than the centre. But the semilunar fibro-cartilages of the knee-joint 
are hollowed, and extremely thin on one of their edges. Only one is 
usually found in each articulation; but that of the knee is an exception 
in this respect, as it sometimes contains two. 

§ 273. The fibro-cartilages of the tendinous sheaths cover the bones 
in those places where the tendons glide over them ; hence they gene- 
rally have a long grooved form. They are developed in the periosteum, 
and are usually composed of interlaced fibres, the direction of which 
is contrary to that of the sheath itself and of the tendon. They are 
generally thin, but become much thicker in certain points, and vary in 
this respect in all parts of the same sheath. Where they are unusually 
thick, we observe a corresponding development of a fibro-cartilaginous 
or osseous tissue in the tendon which glides upon them. We may 
easily be convinced of this in the place where the tendon of the tibialis 
posticus passes under the head of the artragalus to be inserted into 
the scaphoid bone. This arrangement, then, forms real articulations 
in those parts where considerable friction takes place. Something 
similar is seen in the crucial ligament of the first and second cervical 
vertebra, whefe it passes behind the odontoid process of the second. 

§ 274. The annular fibro-cartilages are composed of circular fibres, 
arranged around the circumference of the rounded articular cavities 
which admit of extensive motions, as those of the ossa ilia and the 
scapula. They always grow thinner from their base to their loose 
edge : they confine the motions of the joint by deepening its cavity, but 
not so much as an edge of bone would. 

§ 275. These fibro-cartilages, which adhere on both sides t» the 
adjacent bones, are formed of fibres, the direction of which is perpen- 
dicular to the surfaces between which they are extended, <tnd form 
the articulations called symphyses, (§ 242.) Their form spends upon 
that of the osseous surfaces which they are intended to unite. Hence 
they are almost circular between the bodies of the ^ertebree, irregular 
between the sacrum and ossa ilia, and oblong and square between the 
ossa pubis. They are inserted in the first two o*ses by broad surfaces, 
and in the third by narrow edges. . 

6 276. The texture of the fibro-cartilag^ is composed, as their name 
indicates, of a cartilaginous and of a fibroid substance. These twomasses 
are easily distinguished from each other, and form more or less regular 



244 GENERAL ANATOMY. 

alternate layers. This arrangement is particularly well marked in the 
intervertebral fibro-cartilages. Here in fact there is much more of 
fibrous substance than in the other fibro-cartilages, and it forms white, 
concentric, and solid layers, between which a brownish cartilaginous 
substance seems deposited principally in the middle, while externally it 
is converted into real crucial ligaments. On the contrary, in the inter- 
articular cartilages and in the cartilages of the tendinous sheaths, the 
cartilaginous substance exceeds the fibrous so much, that this latter is 
hardly perceptible, and we might say that it has been injected into the 
other, so that it does not seem so regularly arranged. These fibro- 
cartilages then are allied still more closely with proper cartilages. 

It is a general law that the fibrous substance in a given portion of 
the fibro-cartilage exceeds in a greater or less degree the cartilaginous 
substance. Thus in the fibro-cartilages of the vertebrae, as also those 
of the pubic and sacro-iliac symphyses, the cartilaginous substance 
gradually diminishes towards the circumference, and finally gives place 
entirely to the fibrous substance. Several interarticular cartilages, as 
those of the knee, are attached to the adjacent bones by fibres evidently 
ligamentous. 

§ 277. The tissue of the fibro-cartilages, in relation to the organic 
systems which form it, does not materially differ from that of the carti- 
lages and of the fibrous organs. 

§ 278. The same remark may be made in regard to their proper- 
ties, as they combine those of the two systems. The fibro-cartilages 
are as elastic, but less hard and more flexible, and less brittle than the 
true cartilages. Their extreme solidity causes them to tear with great 
difficulty. They retain the bones to which they are attached very 
firmly together, and favor the gliding of the tendons. This circum- 
stance, added to this that they are but slightly sensible to outward 
impressions, renders them capable of resisting the influence of external 
agents longer than the bones. Thus we sometimes see the bodies of 
the vertebra almost wholly destroyed by chemical or mechanical 
causes, as for instance by an aneurism of the aorta, while the inter- 
mediate fibro-cartilages which unite them remain almost untouched. 

Some fibro-cartilages undergo periodical changes not seen in the real 
cartilages : they become less dense, softer, and moister, and hence 
allow more motion in the parts which they unite. This is seen parti- 
cularly ; n the fibro-cartilages of the pelvis during pregnancy. 

§ 279. T^he fibro-cartilages in the early periods of life, notwithstand- 
ing their sot-^ess, resemble the cartilages which appear at a later 
period, because a t this time the gelatinous substance much exceeds 
the fibrous subsu nce i n a H par t s f the body. This is proved by the 
intervertebral fibro-cartilages and that of the symphysis pubis. As 
the age progresses on \\q contrary, the fibrous substance predominates 
more and more over the cartilaginous. Hence, partly on this account, 
the fibro-cartilages are mucV. softer and more flexible in infants than 
in old men, and hence too, in great part, the stiffness attendant 
upon old age. 



OF THE FIBROCARTILAGINOUS SYSTEM IN THE ABNORMAL STATE. 245 

The ossification of the fibro-cartilages in advanced age is not rare. 
In fact the vertebra are often united with each other by means of an 
osseous substance ; but this union depends more rarely on the ossifica- 
tion of the fibro-cartilages than on the formation of layers of bone on 
the circumference of the two faces .which look towards the bodies 
of the vertebrae But we have sometimes observed ossification of 
the intervertebral fibro-cartilages, and have then found on dividing- 
the vertebral column longitudinally, that several vertebrae were fused 
together, and were blended in one mass. The same is true of the 
symphysis pubis, and the sacrum is often united with the ossa ilia, 

ARTICLE SECOND. 

OF THE FIBRO-CARTILAGES IN THE ABNORMAL STATE. 

§ 280 In respect to morbid alterations, the fibro-cartilages resemble 
the cartilages and fibrous, organs, in the nature of which they equally 
participate. They are but slightly subject to disease : yet the observa- 
tions of Palletta(l) and Brodie(2) establish that inflammation and sup- 
puration sometimes affect them, even before attacking the bones with 
which they are connected. 

§ 281. We not unfrequently see a substance perfectly resembling 
the fibro-cartilaginous tissue formed in some parts of the animal 
economy. This substance most generally assumes the form of round 
masses, very distinct from the surrounding mucous tissue and the sub- 
stance of the organs. Such are the substances which grow in the 
internal genital organs of the female, and especially in the uterus, in 
old maidens ; these formations, usually termed schirrous, but wrongly, 
adhere but slightly to the substance of the uterus, generally pro-' 
ject above its surface, and are easily extirpated ; when cut across, 
they are seen to be composed of different layers and always of two 
substances irregularly intermixed, the cartilaginous and the fibrous. 
These accidental productions have more tendency to ossify than the 
normal fibro-cartilages : but this tendency to become bone does not 
depend entirely upon their size. Bodies similar to them in every res- 
pect are met with, between the vagina and the rectum, in the ovaries, 
the bones, the thyroid and the thymus glands, and more rarely under 
the skin. 



(1) Advcrs. chirurg. prima, p. 189. 

(2) In the Med. chir. trans., vol. iv., p. 258. 



246 GENERAL ANATOMY 

SECTION VII. 

OF THE FIBROUS SYSTEM. 
ARTICLE FIRST. 

OF THE FIBROUS SYSTEM IN THE NORMAL STATE. 

§ 282. The fibrous system (sy sterna fibrosum) was first considered 
generally and separately by Bichat. The term " fibrous system" is 
not sufficiently distinctive, as the fibrous structure is at least as well 
marked in many other systems, especially in the muscles and nerves ; 
but as these are already named, and it would be difficult to imagine a 
better term, and as it expresses the principal character of the system, 
it may be preserved without inconvenience. 

A. GENERAL REMARKS. 

§ 283. The peculiar characters of the fibrous system are, a struc- 
ture evidently fibrous, and a white silvery and brilliant color. It receives 
few vessels, and probably has no nerves. It is but slightly elastic, and 
is entirely destitute of contractility and of sensibility. 

§ 284. This system is expanded generally through the body, but 
nevertheless does not form an entire whole ; for although a communi- 
cation may be demonstrated between those of /ts portions immediately 
continuous with the bones and muscles, those which are connected to 
some glandular organs are on the contrary entirely separated from the 
others. 

§ 285. The external form of this system is not the same in all the 
parts which it embraces, but these may be referred to two. In one, 
the dimensions in length and breadth are almost equal, and much 
greater than the thickness. This is the form of the fibrous membranes, 
{membranoz fibrosoz.) The organs which present it are, 1, the peri- 
osteum ; 2, the dura mater of the brain and spinal marrow ; 3, the 
fibrous capsules ; 4, the fibrous sheaths of the tendons ; 5, the 
aponeuroses ; 6, the tunica sclerotica ; 7, the capsule of the cor- 
pora cavernosa of the penis and clitoris, and that of the urethra ; 8, 
that of the testicles ; 9, that of the spleen; 10, that of the kidneys. 

§ 286. In the second class of fibrous organs, the thickness is greater in 
regard to the other two dimensions, and these fibrous organs are called 
fascicidar, (Organa fibrosa fascicular ia.) This class comprehends 
only the parts connected with the bones or the muscles, viz. 1st, the 
tendons, and 2d, the ligaments. 

§ 287. If we except the fibrous membranes of some of the glandular 
organs, we may easily demonstrate that all the fibrous organs are 



OF THE FIBROUS SYSTEM IN THE NORMAL STATE. 247 

closely connected together. The different parts of the system com- 
municate by the periosteum (§ 285) : hence it may be considered as 
its common centre. In fact, 1 . The cerebral and spinal dura-mater 
fulfills also the functions of a periosteum to the bones of the cranium, 
and to the vertebrae, as it lines their internal faces, and the canals it 
furnishes to the nerves are continuous with the periosteum which 
covers the external face of these bones. 2. The tunica sclerotica 
communicates with the dura mater by means of the fibrous sheath of 
the optic nerve which is furnished by it. 3. The fibrous membrane of 
the penis and clitoris interlace with the periosteum of the ossa ischia. 
4. The fibrous capsules, ligaments, sheaths, and tendons, are also 
united with the periosteum. It is even by means of this membrane 
alone they hold to the bones, from which they are entirely detached 
if it be removed, especially during the early periods of life. 

This explanation of the fibrous system, the idea of which belongs to 
Bichat,(l) is more natural than that of Clarus,(2) who pretends the 
envelop of the muscles is its centre. According to this anatomist, the 
entire muscular system is surrounded by a common, shining, fibrous 
envelop, the internal face of which gives off prolongations which cir- 
cumscribe each bone and muscle, and are called the periosteum, the 
perichondrium, and the perimysion, or which (as the intermuscular 
ligaments) form only layers and extend from the bones to the muscles. 
Clarus pretends that his opinion is preferable to that of Bichat, because 
it considers all the envelops of the different organs as so many pro- 
longations of one single envelop. But it is evident, that this general 
external layer does not exist, for although all the muscles have a 
mucous envelop, this by no means possesses the characters of fibrous 
tissue, so that the communication which Clarus admits between the 
real fibrous sheaths, which circumscribe for instance the muscles of 
the upper and lower extremities, and the mucous sheaths of several 
muscles, as those of the abdomen, the latissimus dorsi, the trapezius, 
&c, and those too of the deeper muscles, or even between these 
sheaths and those of the different fasciculi and the fibres of each mus- 
cle is entirely forced, and cannot be admitted from ocular demonstra- 
tion. 

§ 288. The peculiarities of fibrous tissue consist in its being formed 
of very apparent fibres which have different directions, in its grayish or 
whitish color, and silvery lustre ; they are very solid and powerfully 
resist external mechanical impressions. In several parts of the body 
their fibres are irregular, and cross each other in different directions. 
They are arranged thus in the dura mater, the anterior periosteum of 
the sternum, and in many of the posterior ligaments the ossacrum 
and the ossa ilia. But they are generally regular, and their direc- 
tion is that of the motions performed by the parts, to the union of which 
they contribute more than any other organ ; consequently also in the 
same direction as they are contracted and relaxed. 

(1) Gen. Anat. vol. ii., p. 263. 

(2) Annalen des klinischcn Indituts zu Leipzig, vol. i., p. ii, p. 156. 



248 GENERAL ANATOMY. 

§ 289. Besides these peculiar fibres, the fibrous organs contain also 
mucous tissue and vessels. The mucous tissue forms a layer which 
envelops them externally, and exists also more or less abundantly be- 
tween their fibres. If we judge from what exudes from these organs 
while drying, this tissue contains also fat, although it is not perceptible in 
their recent state. The number of the blood-vessels is not the same in all 
places : in some parts of the system they are numerous, while in others 
but few exist. We cannot clearly demonstrate the presence of nerves. 

In regard to chemical composition, the fibrous system is formed en- 
tirely of gelatin. 

§. 290. The fibrous tissue is but slightly elastic in the recent state, 
but becomes very much so when dried. It does not admit of great 
and sudden extension. Hence, 1, the strangulation which results when 
parts which are more or less completely surrounded by fibrous organs 
are distended ; 2, the fibrous organs tear when suddenly or forcibly dis- 
tended ; on the contrary, they yield very much to a slow and gradual 
extension without tearing, as is seen in dropsies, pregnancy, luxations, 
which take place gradually, &c. In these instances,they become thin to 
a greater or less extent. But we must not confound with this state an 
increase in their mass, their thickening, which arises from a morbid in- 
crease of nutrition ; this sometimes exists alone, and is sometimes at- 
tended with distension, and almost always succeeds diseases of the 
adjacent organs, of the synovial membranes, of the eye, testicle, &c. 

Nor are the fibrous organs capable of a sudden contraction : they 
however gradually contract after unusual distension. 

These organs are very solid, and it requires great force to tear them. 
They tear on account of their slight degree of extension, for when rup- 
tured they are not, or but slightly elongated. They do not extend more 
than they contract under the influence of stimulants. In the normal 
state, they are sensible not to chemical, but to mechanical irritations. 

The fibrous system serves, in great measure, to protect, to envelop, 
and to unite the organs it embraces. Its properties are perfectly in ac- 
cordance with this function. It intimately adheres to the parts it covers 
and unites ; thus the tendons are firmly fixed to the bones and the 
muscles, and the ligaments to the bones. But this adhesion is not 
equally strong in every part. Thus the periosteum is attached to the 
bones less intimately than the above-mentioned organs are to each other. 

§ 291. In the early periods of life, the fibrous system is soft, very 
flexible, extensible, of a pearly lustre, and homogeneous, and its 
fibrous structure is not developed till towards the end of uterine 
existence ; its fibres are fewer and more separated in the beginning. 
Some fibrous organs are proportionally thinner than they afterwards 
are, as the dura mater, the tunica sclerotica and the periosteum. Others 
on the contrary are smaller, as the tendons. The parts which unite it to 
the adjacent parts are much less solid in the early periods of life than 
at an advanced age ; thus the periosteum is more easily detached 
from the bones, and the tendons are less firmly united with the 
muscles and the bones. They gradually become hard, solid, dry, and 



OF THE FIBROUS SYSTEM IN THE NORMAL STATE. 249 

yellowish. The stiffness and immobility which characterize old age 
depend principally on this state of the membrane. Does the fibrous 
system ever change into other organs 1 It has been thought that 
this was the case with some of its parts, and that the periosteum amono- 
others changed to bone, ( §220, 221.) On the other side, it has been 
thought that other fibrous organs, for instance the tendons, were 
formed from the muscular substance. But this last opinion is as un- 
founded as the other, as we shall demonstrate, when speaking of the 
muscular system. Although the fibrous system becomes more con- 
sistent in old age, still it does not regularly ossify, and in man espe- 
cially it does not tend much to this change. The fibrous organs most 
often found ossified, are several ligaments, especially those of the verte- 
bral column. We have some xyphoid cartilages of old men, where 
all the ligaments of the vertebral column and ribs are ossified. Some- 
times all the articulations are united in this manner, so that the whole 
body becomes incapable of motion. We may adduce too the ossifica- 
tion of the proper ligaments of the scapula, which are not unfrequent. 
Accidental depositions of bone in the dura mater are more frequent ; 
but they depend less on the ossification of the fibrous substance than on 
a real production of bone on its surface, and appear in fact less adhe- 
rent to the dura mater than to the arachnoid membrane which lines it. 
The falx is the place where they most frequently occur. It is remarka- 
ble that ossification of the tendons is so rare, because, in the animal 
kingdom, for instance, in many birds, insects, crustaceous animals, and 
to a certain extent in fishes, the change is connected with the normal 
development. 

R. SPECIAL CONSIDERATIONS. 

§ 292. The fibrous organs form, 1, envelops ; 2, they unite cer- 
tain organs ; or 3, they fulfill both these functions at once. The fibrous 
organs of the first kind are membranous ; the second, on the con- 
trary, sometimes assume this form, and sometimes that of fasciculi, ac- 
cording as the form of the organs with which they are related demands. 

§ 293. I. The fibrous envelops are, 1, the dura mater of the brain 
and spinal marrow ; 2, the periosteum and the perichondrium ; 3, the 
tunica sclerotica ; 4, the tunica albuginea, and the membrane of the 
ovaries ; 5, the envelop of the corpus cavernosum ; 6, the capsule of 
the kidneys ; and 7, that of the spleen. 

The most remarkable properties of these envelops are, 1, they have 
the form of sacs, which surround the organs placed under them. These 
sacs are not entirely closed, like those of the serous membranes, but 
have openings in points, which correspond to the entrance or departure 
of vessels, nerves, and excretory ducts. 

2d. If the organ they cover is composed of several layers, or if other 
membranous expansions exist which are necessary to the performance 
of its functions and its preservation, the fibrous envelops form the 
most external layer. In this manner the dura mater and the tunica 
sclerotica are disposed. They determine then, more or less, the form of 
the organs they surround. 

Vol. I. 3 2 



250 GENERAL ANATOMY. 

3d. Their form and their relations with the organs placed below them 
are not always the same in every part. Some appear as simple sacs, as 
the tunica sclerotica, the capsule of the kidneys, and the periosteum. 
Others form compound sacs. These last in their turn are divided into 
two series : sometimes in fact they give off from their internal face pro- 
longations which do not penetrate even the interior of the organ, as is 
the case with the falces and the tentorium of the cerebellum. Sometimes 
they send through the substance of the whole organ a reticular tissue, 
which forms to a certain extent its base, as is seen in the corpus ca- 
vernosum of the penis and the clitoris, and in the spleen and the testicle. 

4th. They have not a uniform thickness. There isno constant relation 
between it and the volume of the organs. Thus the fibrous coat of the 
eye, of the testicle, and of the ovary, is much thicker than that of the 
spleen or the kidney, and almost as thick as that of the brain and the 
spinal marrow. 

5th. All the fibrous membranes have not exactly the same internal 
structure. In some, as the periosteum, the dura mater of the brain 
and the spinal marrow, and the envelop of the corpus cavernosum, the 
fibres are more distinct than in others. Most of them are formed of 
but one layer, but the dura mater has two, which may easily be en- 
tirely separated in the early periods of life. 

6th. Nor is their mode of union with the parts they surround 
every where the same. The dura mater of the brain and spinal 
marrow have no connection with the organs which they envelop ; on 
the contrary, the tunica sclerotica, the renal capsules, and the tunica al- 
buginea are more or less intimately united to the subjacent organs by 
mucous tissue. In the corpus cavernosum, the spleen, and the ovaries, 
the union is still more intimate, as the capsule sends prolongations into 
the very tissue of these organs. This is the case too with the perios- 
teum, although its fibres have no part in the composition of the bones. 

But we observe in respect to this, periodical differences, which may 
generally be referred to the greater proportional thickness of the fibrous 
envelops, during the early periods of life, and to the greater looseness of 
their attachments to the parts below. 

§ 294. II. The fibrous parts which serveat the sametimeas envelops 
and means of union, form the transition of the fibrous organs of the first 
to those of the third series. They usually have the form of membranes. 

These are, 1, The aponeuroses; 2, the sheaths of the tendons ; 3, 
all the fibrous ligaments ; 4, the fibrous capsules of the serous mem- 
branes ; 5, the fibrous capsules of the mucous membranes. 

§ 295. a. The aponeuroses are of two kinds. They serve as a 
covering to the muscles. They are almost always united to these 
organs, but some surround other muscles besides these, and many form, 
in concert with the muscles to which they adhere, envelops for other or- 
gans, and make the parietes of certain cavities. 

§ 296, The aponeuroses of the first kind may be called muscular 
bands, (fascice muscular es.) Their principal characters are as follows : 

a. They sometimes form canals, or sacs, which inclose one or more 



OF THE FIBROUS SYSTEM IN THE NORMAL STATE. 251 

muscles. From their internal faces are detached fibrous sheaths 
which extend to the bone, separate the muscles from each other, are 
often of considerable thickness, almost always give origin to mus- 
cular fibres, and are termed intermuscular ligaments, (ligamenta inter- 
muscularia.) Sometimes they cover the muscles on one side only. 
The aponeuroses of the extremities, of the deep muscles of the back, 
of the recti muscles of the abdomen, are examples of the first arrange- 
ment ; the second occurs in several muscles, where the tendons which 
are inserted into the bones extend to a part of their surface, gradually 
becoming thinner. 

b. They form general envelops only in the extremities. But spe- 
cial envelops exist in many parts, as the aponeuroses of the deep 
muscles of the back, and the sheath of the recti muscles of the 
abdomen. 

c. These muscular bands are more or less evidently formed of seve- 
ral layers of fibres which vary in direction, or are even formed of seve- 
ral folds, as for instance the sheath of the recti muscles of the 
abdomen. 

d. Their thickness is not uniform ; but it is relative not to the vol- 
ume of the muscles they cover, but to the greater or less freedom of 
motion required. They are much thicker and firmer in those places 
where the motions must be more limited, and where the parts require 
to be maintained more firmly in their respective positions. Thus the 
aponeuroses of the palm of the hand and the sole of the foot, are the 
strongest of all the muscular bands. We may consider too as accessory 
means, certain ligaments which cannot be separated but by destroying 
their fibres with a scalpel, as the ligaments of the wrist, &c. 

We ought in fact to arrange here the fibrous sheaths of the tendons, 
for they do not differ from the ligaments, and communicate with the 
muscular envelops. 

e. Usually they have special tensor muscles, or the tendons of the 
muscles, which serve for other functions, and which are attached to the 
bones, adhere to them, and are even blended with them. Thus the 
crural aponeurosis has a proper tensor muscle, and the palmar apo- 
neurosis has two. The tendon of the glutoeus maximus is continuous- 
with the crural aponeurosis, that of the biceps flexor cubiti with the 
aponeurosis of the fore-arm — that of several muscles of the thigh, 
with the fascia of the leg. The plantar aponeurosis is the only excep- 
tion to this rule in man. The functions of these muscles are to make 
tense the aponeurotic expansions in which they are inserted, and thus ' 
fix more solidly the muscles situated below them. 

/ They are generally united to the subjacent muscles very loosely ; 
we must however except their tendinous upper extremities, which are 
usually blended with them, and which even seem to arise from them, an 
arrangement which increases the extent of the surfaces to which these 
latter are attached. 

§ 297. The aponeuroses of the second kind, are attached like the 
preceding by their circumference to the tensor muscles. They are 



252 GENERAL ANATOMT. 

distinguished from the latter by the relations between them and the parts 
below them. We shall take as an example the aponeurotic expansion 
on the anterior face of the abdomen and that on the external face of the 
cranium. The first is made tense by the broad muscles of the abdo- 
men, of which it forms the anterior tendon, and by the pyramidal 
muscles, and the second by the frontal and occipital muscles. All these 
muscles may be considered as digastric, having two bellies separated 
by a large central tendon. 

§ 298. b. The fibrous sheaths of the tendons (vaginas tendinumjibro- 
see) are membranous expansions forming semi-canals, the loose edges 
of which attach themselves to corresponding edges of one or several 
bones which are slightly turned over, so as to produce entire channels 
in which the tendons glide. These tendons are very long in proportion 
to the muscles to which they belong, and are kept firmly in place by 
these sheaths. 

Their general characters are : 

a. They are very thick and solid, and are formed of very apparent 
transverse fibres, except near the joints, where they are extremely 
thin and interrupted, and are formed of oblique fibres which cross. 

b. They and that portion <5f bone to the edges of which they are 
attached, are always lined by the synovial membranes, which, on their 
outer surface, are reflected on the tendons. 

c. They allow a passage to one or several tendons ; most generally 
to several, but this presents two different modifications. Sometimes 
the canal is subdivided by intermediate fibrous partitions, which are 
attached to separate processes of bone, so that there are in fact as 
many sheaths as there are tendons ; this is seen on the back of the 
hand. Sometimes there are no subdivisions, and the different tendons 
are attached to each other by the projection of synovial membrane, 
and are, in fact, inclosed in the same sheath. This is the arrange- 
ment of the tendons of the palm of the hand and phalanges. We 
call the sheaths of the first kind compound, and those of the second 
kind simple. 

We have already remarked that these two kinds of sheaths are con- 
tinuous with the aponeurosis of the extremities. 

The tendinous sheaths and the fibrous agents of union are usually 
developed in the direction in which the hand and foot are flexed more 
than in any other. The former are observed only in the extremities of 
the limbs. The extensor muscles of the toes and fingers are retained 
in place in the carpus and tarsus, only by compound tendinous sheaths. 
In the palm of the hand, on the contrary, besides the strong fibrous 
sheath under which the tendons of all the flexor muscles pass, 
there is a proper sheath for the two flexor tendons of each finger or toe. 

This difference depends, 1st, on the difference in the number of the 
flexor and extensor tendons ; for each finger or toe has two of the for- 
mer and only one of the latter ; 2d, this arrangement of the extensor 
tendons is compensated by the union with them of the interosseous and 



OF THE FIBROU9 SYSTEM IN THE NORMAL STATE. 253 

the lumbricales muscles ; 3d, ruptures of the flexor tendons occur more 
easily than those of the extensor tendons, and their consequences are 
more serious. 

§ 299. c. The fibrous ligaments have sometimes the membranous 
and sometimes the fascicular form. The former constitute the fibrous 
capsules, while the second form the proper fibrous ligaments. All 
these organs have this in common, that their two extremities extend 
from one part of the osseous system to another, and both unite with 
the periosteum ; that they are formed in great part of longitudinal 
fibres ; and that they are usually strengthened by their union with 
other tissues. 

§ 300. The fibrous capsules are always placed outside the synovial 
capsules, and extend from one bone to another. They are rarely per- 
fect : such are only found in the shoulder-joint and hip-joint. But certani 
synovial capsules, as that at the articulation of the elbow, are strength- 
ened by fibres which arise from their edges, and expand in their central 
portions. The fibrous capsules adhere very strongly to the sjmovial 
capsules ; we must, however, except the places where the latter are 
reflected on the cartilages, and where they are united only by an 
abundant and loose cellular tissue. They form sacs open at their two 
extremities. 

§ 301 . The fascicular fibrous ligaments go from one bone to another, 
or, which is more rare, they are extended between two different points 
of the same bone. They expand, 1, on some parts of the syno- 
vial capsules, with which they are more or less intimately united ; or, 
2, they pass over the fibro-cartilages which connect two bones, or 
extend from one process of bone to another, passing directly on the 
symphyses or at some distance from them ; or, 3, they are only ex- 
tended between two bones, and do not strengthen the synovial capsules. 
To this last species belong several ligaments of the vertebral column, 
those which unite the sacrum and ischium, &c. They make the 
transition from those of the first species to those which go only from 
one point to another of the same bone ; and the more, as the bones 
between which similar ligaments exist are entirely motionless or 
nearly so. These last ligaments serve also to multiply the surfaces of 
attachment for the muscles, as well as to unite the bones. The liga- 
ments which attach themselves to different parts of the same bone, 
sometimes turn all around another bone, like a ring, as is seen in the 
annular ligament of the radius and the transverse ligament of the atlas, 
and they unite two adjacent bones, and at the same time confine their 
motions. Sometimes they proceed only from one eminence to another, 
as those situated between the coracoid and acromion processes ; an 
arrangement which affords attachments to muscles, and protection to 
vessels and nerves. 

The relations between the ligaments 1 and synovial capsules are 
generally such as we have stated ;' that is, the ligaments cover the 
capsules externally ; but sometimes they exist within them, which 
generally happens when the weight to be supported requires great 
solidity, as in the hip- and knee-joint. These two articulations are, 



254 GENERAL ANATOMY. 

however, the only instances where internal and external ligaments are 
found. Internal ligaments never exist without external ligaments; 
while the existence of the latter does not necessarily imply that of the 
former. The external ligaments being almost always situated on the 
sides of the joints, so as not to prevent their motions, and to be neither 
compressed nor stretched, they are called lateral ligaments (ligamenta 
lateralia) and also accessory ligaments (ligamenta accessoria) : but 
this latter term is nothing ; for the strength of the articulations depends 
on them, and the synovial membranes is only to facilitate the gliding of 
the surfaces. 

The general form of the ligaments is oblong ; they are rarely trian- 
gular. Their length generally exceeds their breadth, which in turn 
is more than their thickness. Usually they extend in a straight line ; 
sometimes they are annular, and turn on the bone as around an axis. 

§ 302. d. Among the proper serous membranes, the pericardium and 
tunica vaginalis testis are the only ones on which a special fibrous 
layer is distributed, although others also, as the peritoneum, are co- 
vered in several parts by the aponeuroses of the muscles which sur- 
round them. The fibrous layer of the pericardium is very thin, and 
is continuous below with the fibres of the tendinous centre of the dia- 
phragm. These are the sero-jibrous membranes.(l) 

§ 303. e. We may class among the capsules of the mucous mem- 
branes the fibrous tissue which descends along the external face of the 
mucous membrane of the trachea, uniting its cartilaginous rings ; but 
we do not think a similar tissue may be admitted in the ureters, the 
vasa deferentia, and the Fallopian tubes. 

§ 304. TIL The fibrous agents of union are those fibrous parts 
which unite organs separated from each other. Many ligaments which 
do not serve to strengthen and to protect the serous membranes, those 
for instance observed in different parts of the vertebral column, or be- 
tween the sacrum and ossa ilia, make the transition from the fibrous 
capsules to the fibrous organs which only serve as a means of union, 
and in reality belong to this class, formed principally by the tendons. 

§ 305. The tendons(2) are that portion of the fibrous system which 
unites with the muscular system. We ought to refer to it several 
muscular aponeuroses, and the aponeuroses of the second kind, 
(§ 296, 297,) which are only broad tendons. We could then divide 
the tendons into long, and broad or flat. 

The tendons are always united to the muscles by one point at least, 
and sometimes by two opposite points of their surface. In the first case, 
their other extremity is attached to a solid and hard part, usually to a 
bone, rarely to a cartilage. When their two extremities are united to 
the muscular substance, they are catted tendinous intersections, or inter- 
mediate tendons, (intertendines, tendines intermedii.) From this ar- 
rangement digastric or polygastric muscles are formed, or, to speak 

(1) Bichat, On the membranes. 

(2) Isenflamrn, Bemerkungen iiber die Flcchsen, in the Beytragefur die Zerglie- 
derungskunst, vol. i., Lespsic, 1800. 



OF THE FIBROUS SYSTEM IN THE NORMAL STATE. 255 

more precisely, as many separate muscles as there are bellies. This is 
observed particularly when, as often happens, the tendinous intersec- 
tions, are intimately united with the adjacent parts, be it either to bone 
or to other tendinous organs. 

The tendons always extend much beyond the point where they are 
entirely disengaged from the muscular substance. They not only 
cover a part of the outer surface of the muscle and extend, gradually 
growing thinner, and terminate by an edge more or less broken or by 
a kind of pyramid, but they go still deeper into the organ, in the middle 
of which they are seen for some distance after they have become in- 
visible on the surface. It is thus that often, in the penniform or semi- 
penniform muscles, the tendons which appear very short externally 
pass almost through the length of the muscle. 

These two circumstances increase the extent of the surfaces in 
which the muscles are inserted, and consequently their firmness. 

One part of the tendon which covers a portion of the muscle is usu- 
ally situated on its external face. This arrangement belongs not less to 
the common than to the intermediate tendons. Hence the muscular 
fibres which are attached to them almost always proceed from within 
outward. 

The direction of their fibres corresponds perfectly to that of the fibres 
of the muscles, or it is between that of the latter, whether the muscular 
fibres are attached to the two sides of the tendon or only to one. 

Usually the tendons are a little flat, and are rarely round. They 
enlarge at their two extremities, not only on the side where they par- 
tially cover the muscles, but also where they are attached to the 
bones. 

Most of them are single in their whole extent, and are rarely di- 
vided. The latter arrangement offers several peculiarities : 

1st. The tendon presents an opening through which pass other 
tendons belonging to the deeper muscles, which go to be attached to a 
part situated before the perforated tendon. This arrangement serves 
principally to prevent the perforating tendonsfrom deviating: an instance 
is seen in the superficial flexor muscles of the fingers and toes. 

2d. The tendon divides at its extremities, and is attached by several 
slips. 

This arrangement occurs at both extremities, but it is much more 
common in [he end next the muscle than in the other. When met 
with at the extremity towards the bone, this end sometimes divides 
into two equal parts, which are attached to the same bone, as is seen 
at the anterior extremity of the common superficial flexor tendon of the 
fingers and toes ; sometimes it divides into several slips, which are 
attached either to different parts of the same bone, or to the adjacent 
bones, or to the bones of the adjacent parts. 

The superior tendon of the rectus femoris muscle, and the infe- 
rior extremity of the anterior tendon of the external oblique abdominal 
muscle, offer examples of the first arrangement ; the tendons of the 
tibialis posticus and of the peroneeus longus muscles are instances of the 



256 GENERAL ANATOMY. 

second ; and finally, examples of the third are seen in the tendons of 
the common flexors and extensors of the fingers and toes. But we 
must observe that here the muscles rather than the tendons divide, and 
that each muscular belly produced by this divison has its proper ten- 
don. In the flexor digitorum communis longus and in the flexor hallucis 
longus we see the contrary arrangement. 

Usually this division causes several bones which have little motion 
on each other to be moved by a single muscle. Sometimes also, as 
the tendon of the external oblique muscle of the abdomen, it serves for 
the passage of certain organs ; so that it approaches in every respect 
the perforation of the tendons. 

On the other hand, we sometimes see the tendons of several muscles 
unite in one, and attach themselves together to a movable point. For 
instance, in the biceps flexor and triceps extensor muscles of the arm, 
the quadriceps extensor and the biceps femoris muscles, and finally the 
long and short common extensors of the toes. 

§ 306. The fibrous system contains in several parts fibro-cartilages 
and bones, which resemble each other much, as fibres penetrate more 
or less the tissue 4 of the latter. They are especially common in 
the tendons, but are not rare in other parts of the fibrous system ; and 
we may refer to them even the fibro-cartilages to a certain extent. 

We have no better name for these than tendinous cartilages and 
bones.(l) The most constant is that met with high up in the knee, in 
the tendon of the extensor muscle of the leg, the patella. They are 
found also in the hand and foot, in the articulation of the first pha- 
langes of the thumb and the large toe with the carpus and tarsus, and 
in the tendons of the tibialis posticus and of the peronaeus longus. 
They are sometimes found in the tendons of the other fingers and toes, 
even in the anterior joints. They are observed less frequently in 
the upper tendons of the gastrocnemii muscles, or at the articulation 
of the elbow, in the tendon of the triceps extensor. Their form is 
flat and slightly rounded. The distance which separates them 
from the insertion of the tendons is very slight. Their external and 
lateral faces are intimately blended with the substance of the tendons ; 
the internal is incrusted with cartilage, and turned towards one of the 
two bones which move on each other, or is connected with both at 
once. In the carpus and tarsus they are almost always arranged in 
pairs one at the side of the other, while in the knee and in other places, 
even in the anterior joints of the toes, they are unmated, and their form 
is more or less broad. They are generally situated in the joints, oppo- 
site the contiguous ends of the bones, in the tendons which correspond 
to the movable part in which the muscle is inserted by means of 
these, and on the side of which flexion takes place, excepting always 
the patella and the corresponding bone which is sometimes found in 
the elbow. 

(1) Bichat calls them sesamoid bones ; but this term is improper, because it has 
long been applied to other bones of a different character. 



OF THE 11BROUS SYSTEM IN THE ABNORMAL STATE. 257 

Hence it is easy to see that these bodies serve in part to prevent the 
compression of the tendons, especially in rapid motions. But their 
principal use is to change the direction of these same tendons and to 
enlarge their angle of insertion, which adds very much to the power 
of their muscles. 



ARTICLE SECOND. 

OF THE FIBROUS SYSTEM IN THE ABNORMAL STATE. (1) 

§ 307. With regard to the reproductive power of the fibrous tissue, 
we would observe that wounds and lacerations, with or without loss 
of substance, do not heal by the formation of an analogous substance, 
but by the formation of a less firm, less solid, and whitish tissue, which 
is neither brilliant nor perceptibly fibrous. Hence fibrous ligaments 
are not produced in unreduced dislocations. Nevertheless, a condensed 
cellular tissue replaces more or less perfectly the destroyed fibrous sub- 
stance, and its properties differ little from those of the latter. 

§ 308. Among the deviations from the normal state, primitive de- 
viations of the external form are rare, and usually attend anomalies 
of the other tissues. Among these we arrange, for instance, the ab- 
sence of the tendons of the abdominal muscles, that of the ligaments 
of the vertebral column, and that of the dura mater of the brain and 
spinal marrow, &c, in a congenital fissure of the abdomen, of the verte- 
bral column, and of the skull, and that of the tendons and the muscles 
of a finger, when the finger itself is wanting. But the fibrous organs 
are seldom deficient, when the other tissues with which they combine to 
form a part are present — for instance, the tendon alone of a muscle is 
rarely absent, or the tunica sclerotica, when the other membranes of the 
eye exist. Perhaps we should refer to this anomaly the absence of the 
round ligament in the ilio-femoral articulation, although it is almost 
always remarked in circumstances which render it very probable that 
this part has been destroyed. 

The consecutive or accidental deviations of formation, are, 1st, 
lacerations which are seen particularly in the ligaments and ten- 
dons. The ligaments of the joints which have little motion are 
more exposed to them than any other, when these joints are dis- 
located. Lacerations of the tendons supervene principally after 
violent and sudden efforts of the muscles to which they are attached, 
especially when the tendon itself is firmly fixed : they are sometimes 
incomplete when they do not comprehend the whole thickness of the 
tendon. The other deviations of form are, 2d, rigidity, and 3d, relaxa- 
tion, which like the preceding state may become the cause of disloca- 
tion. 

(1) Gotz, De morbis ligamcnlorum ex mutala materiel animalis forma et mif' 
t ura cognoscendis, Hallc^ 1798. 

Vol I 33 



258 GENERAL ANATOMY. 

§ 309. The alterations in the texture of the fibrous organs are, 
1st. Inflammation, which rarely terminate* in suppuration or gangrene, 
but more frequently in the thickening of the substance of the organs. 
Thus the fibrous ligaments alter in white swellings, although they are 
not by any means the only seat of this affection,(l) in which they lose 
their silvery lustre and their fibrous structure ; when the disease is 
advanced, the mucous tissue which surrounds the capsule of the joint, 
the capsule even, and the cartilages and bones, are inflamed and sup- 
purate ; new formations of different kinds are developed around and 
within the capsule: finally the fat and the synovial fluid of the joint 
are hardened and thickened. Still, notwithstanding these changes, the 
disease seems often to affect the fibrous ligaments primarily, for these 
organs are the only ones which are found altered at its commence- 
ment. 

2d. The production of heterogeneous substances within them or on 
their surface. Under this head we comprise the soft gelatinous tumors, 
and the hard, solid, and cartilaginous tumors of the periosteum, and the 
fungous tumors of the dura mater — a name which comprehends very 
different diseases. (2) In osteo-steatoma, another term which com- 
prises morbid states of different characters, the periosteum is sometimes 
affected primarily, often alone, and always when the bone is diseased : 
the first undoubtedly happens when fibro-cartilaginous bodies are 
developed around the cartilages and the bones. 

§ 310. Is the fibrous substance produced accidentally in the body ? 
In fact there are accidental formations in which they occur : those for in- 
stance developed in the uterus, ovaries, thyroid gland, &c; and Bichat 
states that which is sometimes found in the uterus and fallopian tubes 
is an anomalous repetition of the fibrous structure, because composed 
of yellow fibres. But we have never observed that these accidental 
productions perfectly resembled fibrous organs, and they seem to be 
more closely connected with the fibro-cartilages — hence why their 
history is placed after that of the latter. 



(1) A Monro, A white swelling of the knee, in the Edinb. med. essays and obs., 
vol. iv. p. 242.— T. Simpson, Remarks on the white swellings of the joints, ibid. p. 
246.— J. A. H. Reimarus, De tumore ligamentorum circa articulos,fungo articn- 
lorum dicto, Lcydcn, 1757. — B. Bell, Treatise on the theory and management oj 
■ulcers, with a dissertation on white swellings of the joints, Edinburgh, 1778. J. Rus- 
sell, Treatise on the morbid affections of the knee-joint, Edinburgh, 1802.— C. Crow- 
ther, On the disease of the joints, commonly called white swelling, London, 1808. 

(2) Louis, Memoire sur les tumeurs fong. de la dure-mere, in the Mem. de I' Ac. 
de chirurg., vol. v. p. 1.— Wenzel, Ueber die schwammigen Geschwulste auf der 
dussern Hirnhaut, Erfort, 1811.— Walther, Essai sur les fongus de la dure-mere, 
in the Journ. compl. du Diet, des sc. med., vol. vii. p. 118. 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE 259 

SECTION VIII 

OP THE MUSCULAR SYSTEM.(l) 
ARTICLE FIRST. 

OF THE MUSCULAR SYSTEM IN THE NORMAL STATE 
A. GENERAL REMARKS ON THE MUSCULAR SYSTEM. 

§ 311. The muscular system is composed of bundles of reddish soft 
fibres, which of all organs change their volume and form with the most 
facility, and thus produce motion, and occasion the displacement of 
the body or of some of its parts. 

§ 312. All the muscles possess these characters, whatever maybe 
their difference in form. They may, however, be divided into two 
principal classes, which are founded on the connection between their 
activity and the actions of the intellect. These classes are the volun- 
tary muscles, such as obey the will, and the involuntary muscles, which 
do not recognise its power. The muscles of these respective classes 
differ much in their external and internal forms ; but these differences 
do not exclude general considerations, as Bichat thought. (2) 

§ 313. The muscles are composed of fasciculi, placed at the side of 
and upon each other ; and whatever the form of the muscle may be, 



(1) The principal works on the general history of the muscles are : 

1. On their structure and their functions — Barclay, On muscular motion of the 
human body, Edinburgh, 1808. 

2. On their normal structure — Muys, Ariificiosa musculorum, fabrica, Lcyden, 1741. 
— Prochaska, De came musculari, Vienna, 1778. — Prevost et Dumas, Mcmoirc sur 
les phcnomenes qui accompagnent la contraction de la fibre musculaire, in the Journ. 
de physiol. exper. vol. iii. p. 301-339. — Dutrochet, Observations sur la structure intime 
des systemes nerveux et musculaire, et sur le mecanisme de la contraction chez les 
animaux, in his Recherches anatomiques et physiologiques sur la structure intime 
des animaux et des vegetaux et surleur mobilite, Paris, 1824. 

3. On their abnormal structure— Schallhammer, De morbis fibres muscularis, Halle, 
1799. 

4. On their irritability — Zimmermann, De in -Habilitate, Gottingen, 1751. — Haller, 
Mem. sur la nat. sens, et irrit. despart. du corps hum., Lausanne, 1756-1759. — Weber, 
De initiis ac. progr. doctr. irritab., Halle, 1783. — Gautier, De irritabilitatis notione, 
natural et morbis, Halle, 1793. — Croonian lectures on muscular motion, in the Phil, 
trans., ann. 1738, 1745, 1747, 1751, 1788, 1795, 1805, 1810, 1818, etc.— J. C. A. Clarus, 
Der Krampf, Leipsic, 1822. — Luca?, Grundlinicn einer Physiologie der Irritabili- 
tat des menschlichen Organismus, in Meckel, Deutches Archiv.fur die Physiologie, 
vol. iii. p. 325.— G. Blane, On muscular motion, London, 1788; and in Select, dissert., 
London, 1822. — Barzelotti, Esame di alcune teorie sulla causa prossima delta contra- 
zione moscolare, Sienna, 1796. — H. Mayo, Anatom. and Physiological commentaries, 
London, 1822. 

5. On their mechanical laws of motion — Borelli, De motu animalium, Leyden, 1710- 
— Barthez, Nouvelle mecan. des mouv. de I'homme et des animaux, Carcassonne, 
1798. — Roulin, Recherches sur les mouv. et les altitudes de I'homme, in the Journal 
dephysiol. exp., vol. i. and ii. 

(2) Gen. Anat. vol. ii. p. 327. " The general muscular system very evidently 
forms two great divisions— .We shall not then consider them together." 



260 GENERAL ANATOMY. 

its length exceeds any other dimension. These fasciculi are themselves 
composed of fibres, which result from an aggregation of filaments, called 
muscular filaments. The fibres and filaments are as long as the fas- 
ciculi, so that in them the length exceeds the other dimensions. As 
to the fasciculi, they do not usually extend the whole length of the 
muscles, but go more or less obliquely from one edge to another, or from 
the two edges towards the centre. The fasciculi, fibres, and filaments 
are angular rather than round, and at the same time, particularly the 
fibres and filaments, are a little flat. 

The whole muscle, or its smallest filament, is composed of two 
substances, the muscular substance properly so called, and an envelop 
of mucous tissue. The latter, which is termed the muscular sheath, 
(vagina muscularis,) surrounds the whole muscle and afterwards di- 
vides into large tubes, which circumscribe the fasciculi, and again di- 
vide anew into other smaller tubes for the fibres and filaments. 

§ 314. Opinions in regard to the texture of the muscles vary much 
The formation of these organs is doubtless such as has been described 
but we wish to know, 1st, if there are more subdivisions than we have 
mentioned ; and 2d, to determine what is the formation of the finest 
filaments in respect to size and mechanical texture. 

§ 315. In regard to the first, very artificial systems have been im- 
agined. Muys, for instance, states, the fasciculi are composed of 
fibres, these of fibrils, and these last of filaments. There are three 
orders of fibres, the large, middle, and small. The large are composed 
of the middle, and these of the small fibres. There are also three 
classes of fibrils, the large, which unite to form the fibres ; the middle, 
which produce the preceding ; and the small, which are composed of 
filaments. Finally we have large filaments to give rise to small fibrils, 
and others which are smaller and of which the preceding are formed. 
According to this system, each fasciculus will be formed of eight sub- 
divisions. 

But this description is unnatural. True, we can usually divide the 
larger fasciculi into others which are smaller : but these can be reduced 
only to fibres, as the fibres can only to filaments, so that we have 
only three subdivisions. A fasciculus is each subdivision of a muscle 
visible to the naked eye, and it rarely varies in the same muscle. The 
fibres which form it become visible by boiling. They are not all of the 
same thickness, as some are three or four times as large as others. 
The filaments, on the contrary, are about the same thickness in all the 
muscles, so that their number in the fibres varies considerably. 

Authors do not agree in estimating the thickness of the filaments. 
They usually make it considerable. Some(l) consider it l-7th or 

(1) Prevost and Dumas subdivide the muscular fibre into three orders, calling 
ternary fibres those which arc seen on dividing- the muscle lengthwise; secondary 
fibres, those which arc obtained by dividing the ternary ; while the primary fibres 
are produced by mechanical alterations of the secondary. Dut rochet, to avoid con- 
fusion, proposes to confine the term muscular fibre, to those filiform organs wbicfa 
immediately compose the muscles; to give the name of muscular fibrils, to those 
smaller filiform organs which are observed in 'lie intimate tissue ol the muBCulai 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 261 

l-8th, some(l) l-5th, some (2) a little more than l-3d of that of a 
globule of blood. Others, on the contrary,(3) suppose it even greater 
than that of these same globules, stating it to be l-40th of a line, while 
a globule of blood is estimated at 1 -3000th of a line. We can account 
for these differences only by supposing that the filaments have not the 
same size in every part, (although observers generally assert the con- 
trary,) and by supposing that the observations have not been made 
upon one separate filament. 

§ 316. What is the texture of the filaments ? Opinions vary per- 
haps more upon this subject than in regard to their volume. We may 
ask : 

1st. Are these filaments the primary elements of form, or are they 
composed of other elements % The fasciculi, fibres, and filaments often 
appear wrinkled transversely, and to a greater or less depth. Very 
different explanations have been given of this circumstance. Some 
authors attribute it to the crisping of the mucous tissue, the vessels, 
and the nerves surrounding the muscular fibres, and which in certain 
circumstances, especially when boiled, contract so much from place to 
place, that they seem jointed, although we cannot really divide the 
filaments into smaller parts placed lengthwise. (4) Others consider this 
phenomenon as dependent on this, that the filaments are strangulated 
from place to place and articulated, or because they are formed from an 
assemblage of globules or small cells, disposed longitudinally and im- 
bedded in mucous tissue. 



fibres, and the organization of which we cannot distinguish ; and finally to term 
those rectilinear collections of globular corpuscles observed in the intimate tissue of 
muscular organs, the articular muscular corpuscles. These last corpuscles corres- 
pond to the primary fibres of Prevost and Dumas. F. T. 

(1) Prochaska, loc. cit., p. 198. 

(2) Autenrieth, Physiologie, vol. iii. p. 335. 

(3) Sprengel, lnstitut. physiol., vol. ii. p. 125. 

(4) The Wenzels have determined that each fibre is composed of round and ex- 
tremely small corpuscles. The microscopical observations of Home and Bauer 
represent the muscular fibre as identical with the particles of the blood deprived of 
their coloring matter, the central globules of which are united in filaments. Pre- 
vost and Dumas have obtained the same result. These globules are united by a 
hard jelly or mucus, invisible from its want of color and transparency. They 
are united, like a rosary, and form the primary fibre, while a fasciculus of such 
formations arranged in a similar or nearly similar manner, produces, according to 
them, secondary fibres. This arrangement, noticed for the first time by Lcuwen- 
hoek and Hook, has been observed also by Milne Edwards, and Dutrochet. The 
latter, while examining the muscular fibres of the crab, observed that they are com- 
posed of transparent fibrils arranged longitudinally, with numerous globules in 
their spaces : these globules are filled with a transparent fluid, which penetrates 
between their surface of fibrils, to which they seem to adhere but slightly ; for we 
see fibrils entirely destitute of them. The union of these fibrils and corpuscules, 
which he calls muscular, constitutes in his opinion the tissue of the muscular fibre, 
termed by him the fibro-corpuscular muscular tissue. He adds that we often per- 
ceive corpuscules without fibrils : this he terms the corpuscular muscular tissue : 
his opinion is also, that very probably the fibrils, the intimate structure of which we 
cannot observe, are composed of this corpuscular muscular tissue, either articulated 
nr homogeneous, but so small that it escapes the eye aided even by a microscope. 

F. T 



262 GENERAL ANATOLI \ 

We have often observed this appearance, which causes the muscular 
filaments to appear jointed. We have especially remarked in several 
insects, that the muscular fibres were contracted from part to part so 
regularly, that they resembled rosaries. But, we have usually recog- 
nised that in men they were united, were equally thick and slightly 
flattened. As to their component substance, we have never found it 
perfectly homogeneous ; but it always appears formed of darker 
globules or points, contained in a clearer medium ; these must not be 
blended with those large swellings produced by coagulation. 

2d. Whether these filaments are or are not formed of globules, 
are they hollow or solid 1 This question has been answered, sometimes 
in one way, and sometimes in another, and always in accordance with 
some theory, but it is hardly susceptible of a satisfactory solution from 
the smallness of the objects. Most probably they are solid.(l) 

§ 317. The muscles receive numerous large vessels. They are 
generally supplied by several arterial branches, which arise from one 
adjacent trunk. These vessels do not penetrate into the muscle con- 
stantly in one place, and generally they enter nearer the centre than 
the extremeties, and on the inside rather than on the outside. The 
branches at first proceed in the mucous tissue along the fasciculi ; they 
soon divide into an ascending and a descending branch, which continue 
to ramify to its smallest subdivisions ; but the smallest vessels percep- 
tible by the microscope, are larger than the muscular filaments. (2) 
The several twigs, and even the branches, frequently anastomose to- 
gether. The veins form two systems ; the deep seated veins, which 
accompany the arteries, and the superficial veins, which proceed 
alone. They seem to have fewer valves here than in other organs, for 
they are easily injected from their trunks. 

Although the muscles contain large vessels, their red color does not 
depend on the blood which circulates in them, but on their peculiar 
substance. In fact : 

1st. The muscular substance is paler in the fetus, and also in reptiles 
and fishes, and even in the different muscles of the same animal, espe- 
cially in birds, and likewise in man, when we compare the muscles of 
vegetative with those of animal life, although in both the vessels are 
the same in size and number, and even although they are larger, 
and the blood which they contain is redder in the former. 

2d. The muscles of the cold-blooded animals have a reddish tint. 

3d. This color changes in diseases, while the number and the capa- 
city of the vessels remains the same. 

4th. The color of the muscles does not change in those experiments, 
where that of the -blood varies much. If respiration be suspended so 
as to prevent the change of venous into arterial blood, or if venous blood 
be injected into the arteries, the muscle preserves its reddish tint, 
although the color of its blood is altered. 

(1) This is also the opinion of Rudolphi. Link thinks differently, because he believes 
the muscular fibre to be hollow. Mascagni considers it formed of small cylinders, 
the walls of which are composed of absorbents filled with a glutinous substance. 

F. T. 
(2) Fontana, Ueber das Viperngift, p. 392. 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 263 

5th. The truth of this proposition is supported by analogies drawn 
from other organs. 

§ 318. The nerves(l) of the muscles are also very large. Most 
of the nerves of the cerebral system go to these organs. Usually 
the large muscles receive several branches, while the small muscles 
have only one. The nerves of all the muscles are not of a proportional 
size. (§ 174.) The vessels and the nerves generally proceed together. 
The latter ramify like the vessels between the fasciculi and the fibres, 
but they cease to be visible before them, doubtless because it is impos- 
sible to fill their extreme branches, so as to make them apparent. 

§ 319. The forms of the muscles are very different. Usually they 
are solid or hollow, that is rolled on themselves. We may say that of 
all the organic systems, these parts differ the most from each other in 
size, although otherwise similar in structure. In fact, in no other do 
we observe a difference like that existing between the almost invisible 
muscles of the small bones of the ear, and the glutseus maximus. 

§ 320. In regard to chemical composition, the muscles are formed 
principally of fibres ; but they contain also albumen, gelatin, osma- 
zome, the phosphate of soda, of ammonia, and of lime, the carbonate of 
lime, and an uncombincd acid, which Berzelius calls the lactic acid. 

§ 321. The muscles are soft, but slightly elastic, and are easily torn 
after death, so that then they are but slightly solid ; but they are dis- 
tinguished from all other organs by the extraordinary development of 
their power to change their volume and form, to contract and to extend. 
This property is termed irritability (irritabilitas), and it is brought 
into action by agents which have no effect on other organs. It is 
more convenient to call it with Chaussier motility (vis musculi insita, 
vis propria, agilitas, motilitas.(2) 

§ 322. The particulars of muscular motion which belong to general 
anatomy are, 

1st. The phenomena, the changes of the muscles while in action, 

(1) Prevost and Dumas have observed that when a nerve enters a muscle, it 
appears to ramify very irregularly, unless it discovers a marked tendency to direct 
its branches perpendicularly to the muscular fibres, although they cut them also at 
right angles. As the nerve thus ramifies, it enlarges, and its secondary fibres sepa- 
rate, and are distributed exactly as when deprived of their neurilemma. It then re- 
sembles a net of fibres, from which other filaments are separated and enter the mus- 
cle perpendicularly to its proper fibres. But here sometimes there are two nervous 
trunks parallel to the fibres of the muscle which pursue their course at some distance 
from each other, and mutually transmit small filaments which pass across the space 
of the muscle between them, intersecting it at right angles. Sometimes the 
trunk of. the nerve is itself perpendicular to the muscular fibres, and the filaments 
which it gives off expand in thi3 direction, pass through the organ and return, form- 
ing a kind of web. In all these cases the branches of the nerves are parallel to each 
other, and perpendicular to the fibres of the muscle : they either return to the trunk 
which furnishes them, or go to anastamose with an adjacent trunk, so that they have 
no termination, and their relations arc the same as those of the blood vessels. This 
last fact contradicts all previous opinions. F. T. 

(2) Some modern writers, among others Gruithuisen, (Anthropologic, p. 230-236, 
p. 361-364) and Lenhosseck (Medicinische Jahrbilcher cles Oesterreichischen Staates, 
»ol. v. part. i. p. 97-122, part ii. p. 41-64), have attributed to the muscles a particular 
sense, called by them the muscular sense, or the sense of motion but this evidently 
depends on the general perception termed by Reil ccenaeslhesis. In all the sensations 
we experience during muscular action, there is nothing peculiar which may be com 
pared with what we experience from the senses. . F. T. 



264 GENERAL ANATOMY 

2d. The conditions necessary to produce this action. 

§ 323. I. The phenomena of muscular action are, 1st, the muscle 
shortens or lengthens.(l) For a long time the shortening of the mus- 
cle was thought to be its only change when in an active state. When 
it acts, its fibres perform in a single place, or at several points at once 
an oscillatory motion which causes the surface to appear wrinkled : this 
gradually extends to all its parts, and its usual effect is to bring the 
two extremities nearer each other, and to diminish the distance be- 
tween the parts to which it is attached. It is difficult to determine if 
there takes place an alternate motion from the extremities to the centre, 
and from the centre to the extremities, until the latter predominates,(2) or 
if, as is more probable, there is only a motion from the extremities towards 
the centre, so that the alternative mentioned by authors is purely ap 
parent, and depends on a momentary contraction of the fibres whicb 
resembles a kind of oscillation. (3) 

(1) Prevost and Dumas, who think that when the muscle contracts it is unaltered 
except in the direction of its fibres, attribute its shortening 1 to the sudden flexion oi 
these fibres in a zigzag form ; in other words, to the curves of its constituent parts. 
They have observed that the summits of these curves are always situated in those 
parts where the nervous and muscular fibres intersect each other at rig-lit angles. Du- 
trochet made the same remark at the same time, but he has gone farther. Prevost and 
Dumas understood by contraction only the sinuous curve of the muscular fibre con- 
sidered in its mass. They have remarked that it shortens without any flexion, but 
they consider this shortening- as the result of what Bichat calls contractility of tissue ; 
they have not attempted to state the mechanism by means of which this last property 
is brought into action. They admit in the muscular fibre a state of rest, which it 
assumes whenever no cause tends to lengthen it, and think that is only when the 
fibre is in this state in its elastic shortening, that it becomes susceptible of curving - , 
to shorten again, or in other words, to contract. Dutrochet's observations relate 
principally to this pretended state of rest. He has observed that the shortening of 
the fibre without any flexion depends upon the sinuous curve, upon the very minute 
folds of the internal tissue of this fibre, which lengthens by the unfolding of this 
tissue, and shortens preserving its straightness by the twisting or folding of 
this same internal tissue; that the fibre exists in what Prevost and Dumas 
improperly term a stale of rest, when this inner folding is at its maximum ; and 
that then only begins the development of a second phenomenon, that of the sinu- 
ous curve of the fibre; which shortens, and becomes curved by a mechanism simi- 
lar to that which had effected its shortening, while its straightness was preserved ; 
the difference is this, that, in the first case, the phenomenon presented by the fibre is 
internal, while in the latter it is external. Thus Prevost and Dumas considered one 
part of the phenomenon of muscular contraction, that which preserves the straight 
ness of the fibre, as resulting from a simple elasticity foreign in some measure to 
life ; while Dutrochet represents the curve of the intimate tissue of this fibre as being 
as vital as its curve in the mass, since the latter is the result of a fixed and perma- 
nent elastic state, of the elasticity with which the intimate parts of the fibre tend to 
preserve a certain curve which they have assumed by the fact of the immediate 
cause of life, but the vital contraction of the fibre while straight results from an 
elastic state, which varies in degree, and even ceases to exist to a certain extent, by 
the fact of its relaxation. Prevost and Dumas think that it is by means of this short- 
ening without a curve in the fibre, that the contraction of the membranous muscular 
organs, such as those which exist in the parictes of the intestinal canal, takes place, 
whence they conclude that the contraction of these organs differs entirely from that 
of the muscles of locomotion. Dutrochet deduces on the contrary from his 
vations, and the usual course of nature which constantly unites simplicity and urn 
formity of cause, with variety and fruiti'ulness of result, that this difference does 
not exist, and that in both cases contraction depends on the curve of the muscular 
tissue, on an elastic state the cause of which is vital. As to the < ause itself, ne 
differs from Prevost and Dumas, as we shall mention hcrcaftct 1'' T 

(2) Hallcr, Elan, phys, vol. iv. p. 471. 

(3) Barthcz., Now. El. di I". < de I'hommc ; 1706, vol, i, p. 117. 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 265 

Probably also when it has contracted as much as possible, the mus- 
cle does not remain perfectly still and motionless, but this apparently 
permanent state, is in fact a rapid succession of small contractions 
and extensions.(l) 

In shortening, the muscle swells and becomes thicker. 

Its color when in a state of contraction and of relaxation remains 
the same ; it would seem then that its vessels contain as much blood 
in one case as in the other. Rapidity and power of action are both 
very great in the muscles. Speaking, singing, running, &c., prove the 
quickness with which they act. The weight they can raise, notwith- 
standing their force is diminished by different circumstances, proves 
their power to be great. 

But the phenomena of muscular contraction are not the only ones 
which are active. The muscles possess also an active power of elonga- 
tion or extension. 

The phenomena which prove this proposition are, for instance, 
the motions of the iris, the firmness of muscles spasmodically con- 
tracted, which almost always remains even after death, while if con- 
traction was the only vital act, it would cease at death, and relaxation 
would follow ; the different states of the iris which is usually closed 
after death, but is sometimes much dilated ; the stomach is always 
flabby, but often also contracted in its whole extent, or in some points 
only, with so much power that it is distended with difficulty, and 
finally, the force with which the heart dilates. All these facts are ex- 
plained in a forced and unsatisfactory manner, if we suppose that elas- 
ticity alone contributes to fi*tpnsinn. 

This opinion is still more probable, because the contractions of the 
muscles cease or diminish from the influence of the will, and we can- 
not admit this effect has been produced solely by the action of the an- 
tagonist muscles, which have counterbalanced the efforts of those to 
which they are opposed. 

But we cannot demonstrate that extension is the only vital act 
which the muscles perform, and that they contract simply because 
they are elastic ; for contraction is their first change, when they are 
acted on by a stimulus. 

The muscles have then the power of active extension and contraction. 
Barthez(2) has attributed to them a third, called the fixed power oj loca- 
tion, which consists in the power of remaining a greater or less length 
of time in a state of contraction ; but this power is illusory, for con- 
traction is the essence of all the phenomena on which this is founded. 

§ 324. It is asked now, if when the muscle has changed its form, as 
has been stated, it changes also in mass and volume, that is, if it loses 
in thickness as much as it gains in' length, and in case the loss is 
real, in what manner the change in mass or volume is effected % 

(1) Swammerdam, Bibl. nat., p. 845.— Roger, De perpctua Jibr. muse, palp.— 
Woollaston, Croonian lecture, in the Phil, trans., 1810. 

(2) Nouv. elemens dc la sc. de I'hommc, 1806, vol. i. p. 131. 
Vol. I. 34 



266 GENERAL ANATOMT. 

The muscles may augment or diminish in mass. Each of these two 
theories has its supporters. 

Glisson,(l) Goddard,(2) Swammerdam,(3) and Erman,(4) bring 
forward the following experiments in support of the hypothesis, that 
when the muscle contracts it diminishes in volume. They take a 
hollow muscle, for instance, the heart of a frog : it is inflated, tied, and 
then introduced into a syringe, terminating in a narrow canal, and con- 
taining a colored liquid. The liquid lowers during the contractions of 
the. muscle, and on the contrary rises when they cease. The heart 
of the frog, filled with blood, and torn from the body of the animal, be- 
comes smaller during contractions, and larger when it is dilated. The 
same phenomena present themselves, but less sensibly, when a heart is 
deprived of blood, and without a ligature is introduced into the pipe. 
But in these experiments made on hollow organs, it might happen also 
that the cavity only experienced this alternate enlargement and con- 
traction, or that the fluid contained was compressed or expanded. 

Other experiments have been made to arrive at the same results 
with the solid muscles, either with some of these single organs, or with 
entire limbs. A muscle is introduced into a tube, and to its nerve it* 
attached a small silver wire, which passes out through an opening in 
the cork, or the nerve is preserved sufficiently long to pass out of the 
tube. Now if the nerve be irritated directly, or by a metallic con- 
ductor, the fluid is depressed when the muscle is convulsed. Eut from 
the avowal of Swammerdam, the level of the water does not often vary 
in this Rxpfirimenr., and the change which sometimes occurs may be 
satisfactorily explained by the. attraction exerted upon the liquid by 
the silver wire, or by the nerve. 

The experiments with entire limbs are : a man plunges his arm into 
a large funnel-shaped tube ; the orifice is completely closed, filled with 
water, and the arm is moved, the level of the water is depressed during 
the motion, and rises when the arm is at rest. But these phenomena 
do not prove what the experimenters intended in making them ; for the 
size of the limb ought to diminish, because the veins are empty, and 
blood is expelled from them by the action of the muscles. Besides, the 
contraction of some muscles is attended with the relaxation of others 
so that it is always doubtful whether the diminution in size is owing to 
one or the other of these two states. On the other hand, the level of the 
liquid did not vary in a vessel filled with water, into which the half of 
the body of an eel had been plunged, and made to execute the most 
lively motions. (5) The same phenomenon has been observed when 
the experiment has been repeated with the lower portion of the body of 
frogs. (6) 

(1) Opp. omnia, 1691, vol. iii. p. 191. 

(2) Phil, trans., vol. ii. p. 356. 

(3) Bibl. nat., p. 846, 847. 

(4) In the Abkandlungen der Aakademi* tier Wissenschaften von Berlin 1812 
1813, p. 155 170. ' ' 

(5) G. Blane, Lecture on muscular motion, p. 253. 

(6) Barzellotti, Esame di alcune moderne theorie intorno alia causa prossima della 
tonirazione muscolare, Sienna, 1796. 



t»? THE MUSCULAR SYSTEM IN THE NORMAL STATE. 267 

Neither is the increase in the size of a muscle proved by the pains 
which arise in the arm surrounded by a cord,(l) as this phenome- 
non only proves that the muscle which contracts becomes thicker* 

As the experiments which are adduced in support of the first two 
opinions demonstrate nothing evidently, but far from it, and as they 
often furnish no result from whence we could conclude either that the 
muscle diminishes or increases, it remains probable at present that the 
change in the form of the muscle is not connected with a change in its 
mass. (2) But this law is not proved by the experiment in which the 
motion of the legs of a man, placed on the edge of a beam, do not 
cause his body to lean to the side of the leg which moves, (3) nor by 
the assertions of physiologists, who pretend that there is no alterna- 
tive, because the muscle shortens in proportion as it becomes thick. (4) 
Experiment in fact demonstrates nothing, because certain muscles re- 
lax in the proportion as others contract. The assertion supposes a 
demonstration of what is yet doubtful. The recent experiments of 
Erman(5) seem in fact to favor the hypothesis, that the muscles dimi- 
nish during contraction ; for when parts of eels were put into a cylin- 
der filled with water, and having at its upper part a glass tube, the 
contractions produced by a chain communicating by one pole with the 
spinal marrow, and by the other with the muscles of the part, caused 
the liquid to sink evidently in the tube ; and when they ceased, the 
liquid again ascended as much as it had sunk. One objection only 
can be made to this experiment, which is, that some muscles relax, 
while others contract ; but the structure of the fish permits us to say, 
if the muscles of one side of the body only are contracted, all those of 
the separated portion are truly contracted, and this portion may be con- 
sidered as forming but one muscle. 

The color of the muscles is absolutely the same in action and 
repose. Some think it more pale when they act, because the heart, 
which is transparent, when the blood it contains is emptied, is 
naturally more pale than when dilated and full of blood. 

But as the quantity of the blood usually increases in an organ 
acting with more power, and as this increase of itself renders the action 
more energetic, we ought to presume that a muscle contains more 
blood when in a state of contraction, that when it is at rest. Many 
physiologists are also of this opinion. (6) Prochaska likewise believes 
that when the muscle contracts, fluids flow in greater abundance be- 
tween its fasciculi and its fibres, and that this greater afflux causes con- 

(1) Hamberger, Phys. med., Jena, p. 581. 

(2) This is the opinion also of Prevost and Dumas. By putting into the glass 
larger muscular masses in order to increase the effect of a change in volume, whe- 
ther real or supposed, there was no manifest alteration of the level of the small tube, 
whence they concluded, with Blane and Barzellotti, that if the muscle changed in 
the least, it was to a slight degree only. F - T * 

(3) Borelli, De rrwtu animal, vol. ii. prop. 18. 

(4) Sprengel, Instil, physiol. ; vol. ii. p. 149. 

(5) Gilbert, Annalenfur die Physik, vol. x. 1812, p. 1. 

(6) Particularly Cowper, Stuart, and Baglivi. SceHaller, El.phyi. yo1.iv. p. S44. 



268 GENERAL ANAT0M\ 

traction, and obliges the fibres to assume a more tortuous direction. 
The volume of the muscle then really increases a little on contraction, 
but as its vessels are full previously, this increase is so slight, that its 
change is not appreciable. 

The arguments adduced by Haller against this theory, viz. that the 
motion of the heart is involuntary, that we know not why blood should 
flow in a greater quantity to one muscle than to another, that the mus- 
cle is very irritable, and that the artery is not,(l) these arguments are 
of no weight, for irritation of the muscle would cause a more abund- 
ant flow of blood to it, independently of the energy of the vascular 
system, and the relations of the muscle with the will. Besides, it is 
certain from experiments made with this view, that the contractions of 
the muscles are not at least necessarily attended with a greater afflux 
of blood, and that they do not result from this afflux, since on examin- 
ing the section of a muscle with a microscope there is no liquid exuding 
from the wound, neither during nor after the contractions. (2) Con- 
tractions take place even when the blood is coagulated in the vessels. 
The quantity of this fluid has no influence upon them in any manner, 
and although entirely destitute of blood, they contract with as much 
vivacity as when the muscle contains its usual quantity. (3) 

Paralysis from the ligature of the arteries has been considered as a 
powerful argument, that muscular contraction depends on the afflux 
of blood. But this paralysis does not supervene immediately, and 
even when it occurs soon after the ligature of the arteries, it serves to 
prove only that the blood is necessary to preserve the normal state of 
the muscle, and to maintain its fitness for contraction. We have no 
right to deduce from it any conclusion in respect to the cause of con- 
traction. 

§ 325. II. The conditions for the activity of the phenomena of mus- 
cular irritability are :(4) 

1st. The muscle must be living. At death it loses the power of 
changing its form by contraction, although its elasticity continues 
longer, and ceases only when putrefaction commences. The life of 
the muscle depends upon its uninterrupted communication with the 
nervous and vascular systems. When this communication has been 
interrupted, the muscle still preserves its irritability for sometime, even 

(1) Haller, loc. cit., p. 545. 

(2) Ibid. exp. 1-4. 

(3) Barzellotti, loc. cit, exp. 10-12. 

(4) Nasse has concluded from some experiments that the irritability of the mus- 
cles is diminished and even destroyed by water, and has also pointed out the influ- 
ence of this opinion on the theory of various physiological and pathological pheno- 
mena. (Deutsclies Archiv.fur die Physiologie, vol. ii. p. 78.) This fact had been 
noticed previously by Humboldt, (Veber die gereiztc Muskel-und Nervenfascr, vol. 
ii. p. 221, 222,) Carlisle (Philos. trans. 1805, p. 23,) and Pierson (in Bradley, Med. 
and phys. journal, 1807, vol. xvii. p. 93.) It was also demonstrated by Edwards, (Sur 
Vasphyxie des batraciens, in the Annates de cliimie et de physique, vol. v. p. 356-380,) 
and again brought forward in hie important treatise, De Vinfluence des agens phy- 
siques sur la vie, Paris, 1224.) F. T. 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 269 

when removed from the body, because it contains nerves and vessels ; 
this power however is soon lost. 

Probably then the part taken by the nerves and their power as ex- 
erted in the contraction of muscles is merely secondary, and the rela- 
tions between the nervous and the muscular systems are the same 
as those between the systems of the muscles and vessels, viz. the simple 
relations of formation and of nutrition. The contractility of the mus- 
cles is situated undoubtedly in their peculiar substance, but to call this 
power into action, a more active life is necessary. This is derived 
from the nerves and vessels with which the muscles are so liberally pro- 
vided, probably for this very purpose. This view of the influence of 
the nerves is confirmed by the circumstance, that in many muscles, it 
seems to be supplied in some measure by the blood. Thus the nerves 
of the heart are proportionally smaller than those of the other muscles, 
while its blood-vessels are much larger ; and farther, the extensive 
surface presented by the reticulated structure of its internal face is wet 
with blood which is constantly rushing to it. Hence too the reason 
that the derangements of the nervous system do not affect all the mus- 
cles in an equal degree, and that the paralysis, and even the lesion of 
this system by poisons, the removal of considerable portions of it, as of 
the brain, the spinal marrow, &c, do not derange the motions of the 
heart, at least so quickly and to such a degree, as the actions of the 
voluntary muscles, whose nerves are proportionally larger. (1) But 
these lesions of the nervous system are not without their effect upon 
the irritability of the heart, and the total destruction of the central parts 
of this system soon arrest its motion entirely,(2) hence these and 
similar phenomena cannot be considered as proving that this muscle is 
entirely independent of the nervous system. 

But we have no right to assert with Legallois,that this difference be- 
tween the heart and the voluntary muscles depends on this, that the 
heart receives the vivifying principle necessary to manifest its activity 
from the whole spinal marrow, by the sympathetic nerve. (§ 182.) But 
we ought certainly to explain it as we have, from the differences rela- 
tive to the age at which these observations on the influence exercised by 
the destruction of the spinal marrow are made, for the older the ani- 
mal, the more of this cord may be destroyed without a suspension of 
the activity of the heart. (3) 

Muscular irritability has then no relation with the activity of the 
nerves, except by reason of the formative acts necessary for its con- 
tinuance in general, and for its more energetic manifestation. 

But the influence of the nervous system and the power it possesses 
upon the irritability of the muscles is very inferior to that of the blood. 
This seems to be demonstrated by the facts in the experiments made to 
enlighten us on this obscure point. The force and duration of the con- 

(1) Wilson, Account of some experimens relating to some experiments of Bichat ; 
in the Edinb. med. and chir. jour n. vol. v. no. 9. xiii. p. 301. 

(2) Lce-allois, Exper. sur le principe de la vie, 1812, p. 83-105. 

(3) Legallois, loc. cif,, p. 89, 90, 95, 97, 98, 101, 102. 



270 GENERAL ANATOMY. 

tractions is always considerably diminished in the muscles the arteries 
of which have been tied, while a division of their nerves does not pro- 
duce the same results.(l) But these experiments perhaps only prove 
that the influence of the nerve on the continuance of the irritability in 
the muscles does not depend upon its communication with the centre 
of the nervous system, but it possesses a sufficient power independently 
of this same centre, and that consequently it can exercise sufficient 
influence on the blood of the part submitted to the experiment. 

The importance of the blood to the exercise of muscular action 
is demonstrated by the deleterious influence of an anomaly in sangui- 
fication, particularly upon the irritability. This power suffers generally 
before all the others in the morbid states of the circulatory and the 
respiratory systems which renders the change of venous into arterial 
blood imperfect. In the same manner it is extinguished so suddenly 
in the bodies of those persons who die by respiring gases which are 
unfit for the normal formation of the arterial blood, such as the car- 
bonic acid gas, and usually after asphyxia. 

In fact we cannot demonstrate that the nervous system is not affected 
simultaneously in these cases, and that irritability is not extinguished 
by paralysis : an opinion, the less improbable, inasmuch as the ner- 
vous power itself then appears to be more or less enfeebled. 

2d. The living muscle must be in its normal state, not only as re- 
spects form, but its chemical composition, and its power of receiving 
impressions. It will not contract if it has remained inactive too long, 
been too much distended, if compressed or changed into fat, or if ex- 
hausted by too frequent or too violent contractions. 

3d. A stimulus must act upon the muscle which must be propor- 
tional with its power of receiving impressions. (2) 

§ 326. The phenomena of irritability are not the same in all muscles. 
They vary in regard, 1, to their duration ; 2, to their extent ; 3, to 
their rapidity of motion ; 4, to the nature of the stimulus which calls 
them into action. Usually the same muscles present the same phe- 

(1) Fowler, Experiments and observations relative to the influence of the Jluid lately 
discovered by Galvani, London, 1793. 

(2) As the extremities of the nerves meet the muscular fihres at right angles, Pre- 
vost and Dumas conclude that the galvanic current excited in passing over these ner- 
vous filaments causes them to approximate, and that these filaments bring with them, 
the fasciculi of the muscles to which they are attached, which produces the folding 
of these fibres. Thus, according to their theory, the nerves are the only organs of 
contraction, and the muscular fibres are inert parts, designed only to obey the 
nervous filaments. Dutrocbet, on the contrary, maintains, that the contraction or 
curve of the muscular fibre depends on the development of an elastic force which is 
itself caused by certain molecular phenomena, so that the muscles act as springs. 
He considers the muscular fibres as solids, which, from the influence of certain ex- 
ternal or internal causes, assume either in their mass or intimate parts a curved po- 
sition, attended with an elastic force which tends to cause this position to be retained. 
From his view of the subject, it follows that muscular contraction is a real pheno- 
menon of elasticity, but of an elasticity which appears and disappears successively 
with the curve which attends it, so that as elasticity is, in final analysis, a phenome- 
non of molecular action, contraction also is found in final analysis, to depend on a 
certain mode of action in the molecules or the corpuscles which compose the organ- 
ized solids. One may see that this theory is directly opposite to that of Prevost and 
Dumas. F. T. 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 271 

nomena in all individuals, and the action of the whole muscular sys- 
tem is brought into play in the same manner by the same circumstances, 
so that the exceptions we sometimes find are much less proper to 
overturn general laws, since the exact knowledge of the causes which 
produce them will demonstrate that they depend precisely on these 
laws. 

§ 327. 1st. There is not a single muscle which does not pos- 
sess the power of contracting some time after the intellectual pheno- 
mena, and consequently voluntary motion have ceased, even when it 
has been separated from the body. The circumstances are rare where 
irritability is extinct in the whole muscular system of a man before 
one hour is elapsed : but this faculty is lost in some muscles much 
sooner than in others. 

It is generally admitted that it remains longer in the involuntary 
than in the voluntary muscles. The following has been established as 
the scale of its duration in the different organs, viz. the heart, the 
intestinal canal, the stomach, the diaphragm, and the voluntary mus- 
cles ; it remaining longest in the first.(l) 

But this rule is often subject to exceptions. Haller himself, to whom 
we owe the scale just mentioned, has frequently known irritability re- 
main in the intestinal canal longer than in the heart. (2) Zimmermann 
has found it remain longer in the diaphragm, and CEder in the other 
voluntary muscles. Froriep and Nysten assert that irritability dis- 
appears soonest in the bladder, the intestinal canal, the stomach, and 
the esophagus, and continues longer in the muscles of animal life. (3) 

Some experiments might induce us to suspect that the difference in 
the duration of irritability depends on that of the stimulus employed : for 
several naturalists have found, that although the heart contracts longer 
than any other organ under the influence of mechanical agents, it be- 
comes insensible to galvanism sooner than the voluntary muscles. (4) 
These phenomena are very remarkable, as they imply that irritability is 
modified by the nature and the mode of action of the natural exciting 
causes, in this respect, that during life the natural stimulus of the 
heart is also a mechanical impulse, while the muscles are excited to 
contract by an agent very similar to the galvanic principle, if not 
identical with it. This hypothesis seems more probable, as in other 
experiments, the voluntary muscles when they were covered by 
the skin, preserved in fact their power of contraction longer than the 
heart, even under the influence of galvanism, but still they became in- 
sensible to the action of this stimulus much sooner than this organ 
when they were exposed like it, and when their temperature was re- 
duced to the same level v '5) because the presence of a fluid capable of 
being vaporized, contributes to produce the phenomena of galvanism. 

(1) Haller, Mem. sur lesparties sensibles et irritables, vol. ii., p. 257. 

(2) Ibid., p. 340. 

(3) Voigt'a Magazin, vol. vi., p. 336. 

(4) Giulio in Voigt's Magazin, vol. v., p. 161. 

(5) In Voigt'a Magazin, vol. vi., p. 337. 



272 GENERAL ANATOJMT 

But more recent experiments made with the utmost care on man and 
animals seem to demonstrate that the difference in the duration of irrita- 
bility does not depend on the nature of the stimulus.(l) The scale 
established by them is not the same as that mentioned by Haller. 

According to these experiments, irritability is lost, 1st, in the left ven- 
tricle of the heai't ; 2d, in the large intestines ; 3d, in the small in- 
testines ; 4th, in the stomach ; 5th, in the bladder ; 6th, in the right 
ventricle, the esophagus, and the iris; 7th, in the voluntary muscles^ 1st, 
in the muscles of the trunk ; 2nd in those of the lower and those of the 
upper extremities, and finally in the two auricles, the right auricle 
preserving its irritability the longest. 

That irritability remains longer in the voluntary muscles, is also 
demonstrated by the circumstance, that water distilled from the 
laurel or from bitter almonds, and placed in contact with the stomach 
and the brain, renders the heart insensible to the most powerful stimu- 
lants in ten minutes, while the voluntary muscles move several hours 
after. (2) 

2d. The extent of motion is not the same in all irritable parts. In 
general, we may admit that the hides, the lymphatic vessels, and the 
intestinal canal, experience the most considerable changes in then- 
volume, for they are susceptible of dilatation and of contraction to an 
almost incredible extent. 

3d. These parts too are extended and contracted with the greatest 
rapidity. 

4th. The nature of the stimulus to motion is not the same for all the 
muscles. Thus light is the specific stimulus of the iris ; the heart con- 
tracts with more power from a mechanical irritation, and its motions 
continue much longer and with greater energy when the irritant acts 
on its internal face, than when in relation with its external face. In 
general, the stimuli are internal or external. The first arise from the 
nervous system, the others are applied directly to the muscles. The 
former may be termed immaterial, the latter material. All the mus- 
cles are susceptible of receiving impressions from these two orders of 
stimulants, but there are several immaterial agents which have no 
action upon certain muscles ; such as particularly the stimulus of the 
will, whence arises the division into the voluntary and the involuntary 
muscles (§312). Still the changes in the activity of the brain produce 
analogous phenomena in all muscles, even in the involuntary. The 
passions modify the action of all the muscles in the same manner : 
anger quickens the motions of the heart and of the intestinal canal, 
even without the aid of the will ; it heightens the activity and increases 
the power of the voluntary muscles. The opposite effects of fright 
and fear are experienced also in all the muscular system. 

§ 328. The degree of muscular activity is modified in many ways 
by different circumstances. Generally its power is in direct ratio with 

(1) Nysten, Reck, dc phys. ct de chimie pathol., 1811, p. 321. 

(2) Himly, Commcntatio dc mortc, Gottingen, 1794, p. 57. 



OF THE MUSCULAR SYSTEM IN THE NORMAfc STATE. 273 

the perfection of the organization of the muscles. In fact the power 
of the contractions may be increased even in those muscles which are 
less perfectly organized and not so well nourished ; but, other things 
being equal, the muscle which receives more nutrition always con- 
tracts with more power than that which is less developed. We have 
before spoken of the influence of the blood and the nerves upon irrita- 
bility (§ 327). 

The duration of the irritability after death, or the cessation of the 
intellectual phenomena, depends much upon the kind of death, the 
state of health during life, and the circumstances in which the muscle 
is placed after death. 

Usually irritability continues a longer time in proportion to the good 
health of the subject, and to the rapidity of death. In a robust man, 
the right auricle contracted nine hours after the head was severed from 
the trunk,(l) while, when the disease has lingered a long time, it is 
entirely extinct at the end of the first hour. (2) It disappears very soon 
in the bodies of those individuals who have died from chronic diseases, 
where the process of nutrition was affected. The diseases which pass 
through their periods rapidly, have no influence on the duration of irri- 
tability ; so that it remains even a whole day in those patients who have 
died from inflammation of the lungs, aneurism of the heart, apoplexy, 
and even nervous fevers. 

But there are certain circumstances where irritability disappears im- 
mediately, even in those who have enjoyed the best health ; as in 
death caused by lightning, by certain poisons, by violent blows on the ab- 
domen, by great efforts, &c. Different external agents acting on the 
body, also cause it to disappear promptly after death : thus hydrogen 
gas, carbonic acid gas, and more especially sulphureted hydrogen gas, 
paralyze the muscles with which they are in contact. 

§ 329. Besides the vital faculty of entering into action from the 
power of stimulants, the muscle possesses still another, which is not 
necessarily connected with life, and which may be termed with Bichat 
extensibility, contractility of tissue, or with Haller, dead force. It is by 
this property that the muscle distends itself when mechanical forces 
act upon it. Thus the muscles of the abdomen are distended during 
pregnancy, in ascites, and the muscles generally by the effect of tu- 
mors which are developed in the subjacent tissues, the heart by the 
accumulation of blood, the bladder by that of urine, the muscular tunic 
of the intestine by the unnatural retention or by the abnormal develop- 
ment of foreign substances, as air or fceces, within it, and finally all the 
muscles by the action of their antagonists. 

As soon as this extending power ceases to act, the muscle returns 
to the volume which it possesses naturally in a state of repose, and 
it is not distended by a strange power. When a dead muscle is divided, 
if it be distended, the cut portions contract and separate. The short- 
ening of the muscles of the stump after amputations depends on this 

(1) Nysten, loc. cit., p. 318. 

(2) Nysten, loc. cit., p. 367-383. 
Vol. I. 35 



274 GENEIUt ANATOMY. 

power of contractility, whence the bones which were at first con- 
cealed in the soft parts gradually appear. 

These phenomena do not cease till putrefaction commences. But 
are they not phenomena of life % We have seen them even in muscles 
which have been soaked for several hours in a strong solution of 
opium, and in animals killed by electricity, as also in cases where these 
organs have not been submitted to similar agents. Bichat divided the 
muscles of a limb, the nerves of which had been cut ten days previ- 
ous; contractions occurred as forcibly as in those muscles whose 
nerves had not been divided : and farther, a certain retraction of the 
muscles is always observed in the amputation of a paralyzed limb. 
Butwe do not consider these facts as demonstrating that the phenomena 
of which we treat are not the results of life ; they only prove that they 
are the results of a vitality much slower than that which exists when 
the phenomena of irritability are produced ; besides, the duration and 
the force of the phenomena of irritability do not differ when ex- 
amined comparatively in the healthy and the paralyzed muscles of the 
same subject.(l) Probably all the changes in the form of the muscle 
depend upon the same force which only acts with more energy while 
the life of the nerves is not extinct, but is preserved for some time after- 
ward, although it does not seem to us probable that the stiffness of the 
Cadaver is a vital phenomenon of the muscles, as Nysten thinks. (2) 

§ 330. The muscles are not very sensible, although they receive 
numerous nerves. 

§331. The principal differences presented by the muscular system 
at different periods of life are as follows : 

During the earliest periods of "uterine existence this system is not 
distinct from the fibrous, with which it forms a whitish mucous mass. 

The muscles are at first very soft, have no apparent fibrous struc- 
ture, and are much paler than they are afterwards. The fibrous struc- 
ture does not develop itself in them till toward the beginning of the 
third month, and is not visible then unless they are immersed in 
alcohol. From our researches it seems that the large divisions of the 
muscles, the fasciculi, form before the smaller ones, a remarkable phe- 
nomenon, because we observe also in the animals of the inferior classes, 
that the final subdivisions of the muscles in which length predominates 
are proportionally and even absolutely larger than in the superior ani- 
mals, and we see only globules or small points in the centre of those 
large fasciculi into which the muscle is divided. They are also thinner 
and more feeble. The heart alone is an exception to this rule : for it is 
proportionally much larger in the early than in the subsequent periods 
of life. 

It follows, from the great difference in the respective proportions of 
the regions of the body, that the same muscles have not at all times 
the same proportional volume in regard to each other or to the whole 
body ; those of the upper half of the body, of the head, the neck, and 

(1) Nysten, toe. cit., p. 369. 

(2) Loc. tit., p. 384-420. 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 275 

tire back, are much more developed than those of the lower extremities. 
Thus, for instance, some small muscles of the neck are much larger 
than the gluteus maximus, which finally exceeds all others in volume. 

The loose part of the tendons is already proportionally as long and 
as strong as it is afterwards, but these organs are less apparent and 
less developed in the interior of the muscles. 

According to some writers, the muscles of the fetus are less irritable 
than those of the adult ; and the degree of facility with which they con- 
tract, and the duration of contractions is much less, the nearer the fetus 
is to the period of its formation. But these assertions are contradicted 
by several facts : 

1st. By the greater tenacity of life in the fetus and the newly born 
animal, and the entirely opposite phenomena that irritability presents 
in similar animals, as the cold-blooded and the hibernating animals 
during their period of hibernation. 

2d. By the general law, that the power and degree of effort .with 
which muscles are endowed during life, is usually in an inverse ratio 
to the facility with which irritability is called into action and to its 
duration, so that the newly born animal resists longer and more easily 
the action of cold,(l) of the irrespirable gases and anomalies in respira- 
tion. (2) Experiments carefully made have convinced us, times with- 
out number, that irritability remains after death in the newly born 
animal longer at least than in the adult. We have further found no 
trace of it at the end of an hour and thirty minutes in an old hamster, 
while the muscle of a hamster killed immediately after birth con- 
tracted eight hours after death by merely touching it. Irritability was 
also extinct in an hour and forty-five minutes in an old rabbit, while it 
remained two hours and thirty minutes in a rabbit three days old. 
We have almost always found its duration etmally long in the newly 
born animal ; often longer, rarely shorter. 

The contractions always appeared to us to be made with more 
energy in the young than in the old animal. In fact, in the latter we 
even perceived that slight convulsions only took place, while in the 
other the muscles always shortened sufficiently to produce for a long 
time a sensible motion in the lirnb to which they belonged. 

Some time after birth the muscles become redder and stronger, but 
they remain for a long time round, soft, and with more of gelatin than 
of fibrin. It is only when the growth is finished, that they become 
thick, angular, have more cohesion, more solidity, that the red color is 
well marked, and that they act with all their power. They acquire 

(1) W. Alexander, in Physiological and experimental essay on the effect of opium 
on the living system, in the Memoirs of the Manchester Society, vol. i., London, 1815, 

(2) Here we refer to a multitude of facts proving that young animals have perished 
less quickly under water and in the irrespirable gases : that newly born infants who 
have been immersed for several days, have been taken out alive ; and that the ab- 
sence, the obliteration, or the contraction of the pulmonary artery has been sup- 
ported without inconvenience, or at least with slight trouble, for weeks, months, aud 
even years. 



276 GENERAL ANATOMF. 

these qualities more perfectly, as the subject enjoys better health, and 
they are more exercised. Their redness, as well as their cohesion and 
force, gradually diminish, while, on the contrary, they become harder. 
Their motions are less extensive and less certain. 

§ 332. The muscles present also differences dependent on the sex. 
Other things being equal, they are rounder and feebler, less solid and 
less vigorous in the female than in the male. We cannot, in the actual 
state of our knowledge, resolve even probably the question if there are 
differences relative to the races of men. However, it is possible that 
the anomalies which degrade us to the class of animals are more com- 
mon in the inferior than in the superior races. 



B. OF THE MUSCLES OF ANIMAL LIFE._ 

§ 333. The muscles of vegetative and those of animal life differ so 
essentially in all points, that, notwithstanding the general considera- 
tions into which we have entered in regard to the muscular system in 
general, it is indispensable to study the two series separately. We 
commence with the muscles of animal life. 

§ 334. The muscles of animal life form a great part of the nrrss of 
the body, in fact nearly as much as all the other organs united. They 
are generally inserted around the bones and represent the forces which 
move these levers. They are particularly numerous and powerful in 
the extremities. Their formation is more or less confined in all parts 
where the principal functions of life are developed, that is, in the cra- 
nium, the abdomen, and the chest. 

§ 335. These muscles form solid masses, the fasciculi of which, 
having a straight direction, attach themselves by their two extremities 
to certain parts of the fibrous system, the tendons, by means of which 
they adhere to the periosteum which unites them to the bones : at least 
this is their usual arrangement. It is seldom that a muscle is not at- 
tached to a bone, or that it is inserted by one extremity only, and that 
its fasciculi by folding on themselves give origin to rings. Most of 
the sphincters, the orbicularis palpebrarum, the orbicularis oris, the 
sphincter ani, and the constrictores pharyngis do not adhere to the solid 
parts on which they act ; they take a point of support from them. The 
muscles which are attached to the bones by only one extremity, and 
which are designed to move the soft parts only, are found principally 
in the face, in the buccal cavity, and in the organs of generation. The 
annular muscles offer no appearance of tendinous structure, or at least 
present it only in those narrow points where they unite to the adjacent 
solid parts, or in those where they arise from the bones, and never in 
the places where they are continuous with those soft parts which they 
put in motion. 

§ 336. The tendons are always much thinner than the muscular 
substance. The muscular and tendinous substances never separate 
suddenly, but we see them alternating together constantly for a greater 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 277 

or less extent. When the tendon is broad but short, it almost always 
eends upon the two faces of the muscle, and between its fasciculi 
small bands which gradually grow thinner and thinner : when it is 
long and narrow, it plunges between the muscular fibres in the form 
of a pyramid which gradually diminishes in thickness. The relation 
between the tendon and the muscle varies much. Some very largo 
muscles have small tendons, as the glutseus maximus, while in others, 
as the palmaris longus, the soleus, &c, the tendon is much larger than 
the muscle. 

§ 337. Generally the tendons are found only at the two extremities 
of the muscles, and they may be considered as their integral parts. 
The central fleshy portion of a muscle is called its belly {venter) ; we 
term the upper tendon, or in general the tendon attached to the most 
fixed point, the head (caput), and the opposite extremity the tail (cauda) 
of the muscle. We term the fixed point (Punctum adhesionis, P. 
fixum) that to which the head is attached ; while the opposite point is 
termed the movable point (Punctum insertionis, P. mobile.) The muscle 
usually contracts towards the former. The muscles are almost always 
fixed by an upper and a lower tendon to two bones, one of which is 
more movable than the other. In the rarest cases, 

1st. They are attached to the bones by one of their extremities only, 
the other being fixed on the soft parts, either that they may unite by 
this extremity with other muscles which act in an opposite direction, 
as is seen in the muscles of the anus and most of those of the genital 
organs, or, as in many muscles which pass upon the capsules of the 
joints, that they may be attached to other organs which they are de- 
signed to move. 

2d. Their two extremities are loose, and when they contract they 
move only the skin situated upon them, and to which they adhere in- 
timately, as for instance the platysma myoides muscle. 

But it sometimes happens that we find tendons in one or several 
parts of the extent of the muscle which then is divided into several 
bellies. We usually find only one of these intermediate tendons, 
termed tendinous intersections (intersectio tendinia.) The muscles 
which present this arrangement are called digastric (biventres, digas- 
trici.) Such are seen in the lower jaw, in the neck, and nucha, as the 
biventer maxilloz inferioris, the biventer cervicis, the complexus cervicis, 
the stemo-hyoideus, and the omo-hyoideus. 

The recti muscles of the abdomen present several tendinous inter- 
sections, which are sometimes four in number. These intersections 
usually extend the breadth of the muscle, but sometimes, (as the up- 
per one of the rectus muscle) they occupy only a part of it. They 
are almost always short in proportion to the length of the muscle, 
while their breadth equals that of the muscle. The dividing tendon 
of the digastricus is an exception to this rule. 

These tendinous intersections, in fact, divide one muscle into several. 
They furnish several fixed points, towards which the fibres contract, 
and between which they can extend, 



278 GENERAL ANATOMY. 

This arrangement then increases the contractile power of the muscle 
and its force of resistance, no fibre of which has an extent equal to its 
whole length. Hence why tendinous intersections are found particu- 
larly in those muscles which are thin and long in proportion to their 
other dimensions. Generally they do not change the direction of mo- 
tion ; they however produce this change in the digastricus, the ante- 
rior and posterior bellies being united at an obtuse angle, by means of 
an intermediate tendon which is itself attached to the byoid bone. 

§ 338. Generally, many muscles act in the same direction, and 
produce the same change in the parts they move, and almost always 
contract simultaneously: hence they are called congenitals. Others act 
in opposite directions, and are called antagonists {antagonists). The 
first occupy the same region, are attached to almost the same points, 
and are placed more or less internally or externally, above or below, 
at the side of, or over each other. The antagonists are situated in op- 
posite regions. All the motions of the different parts of the body may 
be referred to two, whether they are removed from or approach each 
other. One part receding from another approaches a third. These 
two effects are produced by the same muscles, but the different mo- 
tions receive other names, according as the synonymous parts 
placed at the side of or opposite to each other are approximated or 
separated, or according as the parts of a whole which move in the same 
direction, but which, although united, are still movable on each other, 
experience a similar change in their respective situations. 

The first is abduction and adduction, produced by the abductor and 
the adductor muscles ; the second, flexion and extension, performed by 
the flexor and the extensor muscles. Abduction and extension do not 
essentially differ, since the result of both is to displace, in the same or 
nearly the same direction, two parts which at first are situated near or 
at the side of each other, as are for instance two synonymous limbs, 
the fingers of the same hand, or the toes of the same foot, and which 
in the second case, succeed from above downward, as the different di- 
vision's of a limb. Adduction and flexion are also the same phenomena 
at bottom, since both diminish the distance between adjacent parts, 
and establish a difference in the direction of parts which are united. 
In both cases, the faces of the part which changes its form preserve 
the same relative situation, because the same points of its circumference 
continue to face or to be opposite to each other, although they are 
moved from or towards each other. But there is a second kind of mo- 
tion, in which the part turns around its axis, so as to present succes- 
sively to the adjacent parts different points of its circumference. This 
is called rotation, and comprises two kinds : rotation inward, and ro- 
tation outward, according as parts at the side of each other are ap- 
proximated or separated ; hence a third kind of antagonist muscles, 
rotators inward and rotators outward. These motions are rarely ex- 
ecuted by a single muscle. The motion of a part in a given direction 
results almost alwaya from the contraction of several congenital mus- 
cles ; hence we have, at least in parts of any magnitude, several flex- 



OF THB MUSCULAR SYSTEM IN THE NORMAL STATE. 279 

ors and extensors, several adductors and abductors, several rotators 
inward and rotators outward. 

§ 339. The antagonist muscles, and using this denomination in its 
most general sense, the flexors and the extensors, differ not only in the 
characters which divide the muscles into several sections, but also in 
other different circumstances, so that we may consider these two 
classes as the most important. 

Their principal distinctive characters are, 

1st. The flexors, generally speaking, are stronger than the exten- 
sors^ 1 ) Hence the limbs are more or less flexed when the will ceases 
to act, or when in a state of entire freedom, in paralysis, in sleep, in the 
softening of the bones, in subjects where the muscular system is debili- 
tated. The flexors are attached to the bones which they move, far- 
ther from the centre of motion, than the extensors are : their direction 
is less parallel to that of the bones, so that their insertion takes place 
at a more obtuse angle, and is consequently more favorable. This 
angle enlarges as the muscle acts, on the contrary it decreases when 
the extensors contract. The nerves of the flexor muscles are lamer 
than those of the extensors. 

2d. A difference is said to exist between the extensor and the flexor 
muscles, in regard to their excitability ; that they contract only under 
the influence of one pole of the galvanic chain, and this pole dif- 
fers for each class of muscles.(2) Thus it is asserted that the flexors 
contract only when the silver pole is in contact with the central extre- 
mity of the nerve, and the zinc pole with its muscular extremity, 
while the contrary is the case with the extensors, and that both re- 
main still when the poles are reversed. 

Still the experiments adduced in support of this proposition do not 
seem to establish its truth, and are well explained by the greater power 
of the flexor muscles, so that Ritter's law does not differ from it. At 
least it is not correct to say, that the flexor and the extensor muscles 
contract only in the circumstances which have been mentioned for 
even when these circumstances are unfavorable, the greater force of 
the flexor muscles allows them to contract sensibly, while the ex- 
tensors do not contract. 

§ 340. The external form of the muscles varies much, 1st, in regard 
to their complexity. Many, and almost all, arise by a single head, and 
terminate by a single tail fixed to a single point : these are the simple 
muscles (musculi simplices) : others divide at one of their extremities 
into several bellies ; these are the compound muscles (musculi com- 
positi). The division exists sometimes at the movable extremity, as in 
the common flexors and the common extensors of the fingers and of 
the toes, the muscles of the abdomen, those of the back, &c. ; and 
sometimes at the opposite extremity, as in the biceps flexor cubiti, the 

{1) Richerand, in the Mem. dc la soc. mid. d'emulation, vol. iii., p. 161, 1799.— 
Elem. dc physiol., vol. ii., p. 213. 

(2) Ritter, Bcytragc zur nahcrn Kenniniss des Galvanismus, Jena, 1805, vol. ii. nt> 
3, 4. no. ii. p. 65.367. l 



280 GENERAL ANATOMY. 

biceps femoris, the extensors of the fore-arm and of the leg, &c. The 
result of the first arrangement is that a simultaneous motion is im- 
pressed upon different parts of the same muscle. In the second kind, 
1st, the effect is increased ; 2d, when all the different bellies act, the 
motion produced by them is modified ; as, for instance, the leg is at 
once extended and drawn outward or inward ; finally, it follows that 
when the muscle acts in a direction opposite to what is usual, that, is, 
when its bellies contract towards the most movable point, several parts 
are put in motion at the same time. 

Among the simple muscles are some which in some measure foim 
the transition from the .simple to the compound muscles. In fact there 
are several which, although arising by a single belly, and terminating 
by a single tail, are still composed of a greater or less number of 
smaller muscles, the fibres of which are extended in different directions, 
and are inserted into the common tendon by small tendons : such arc 
the deltoides and the subscapularis muscles. 

As to the compound muscles, those which are the least so consist in 
two layers of fibres, terminating by a more or less acute angle in a com- 
mon tendon situated between them. These are called the penniform 
muscles (musculi pennati). The rectus femoris anticus and the flexor 
pollicis longus are examples of this arrangement. 

Another kind of compound muscles comprehends those of two or 
more bellies, which we have mentioned before (§ 337). 

In the most simple muscles the fasciculi have exactly the same 
direction. But the direction, and the relation between the length of the 
fasciculi and the filaments with the length of the muscle, are not ths 
same in all the simple muscles. Sometimes the direction of the 
fibres agrees with that of the whole muscle and of its tendon. In this 
case the length of the muscular fibres is the same as that of the whole 
muscle, and it is straight. This is seen in the sartorius and in the bi- 
ceps flexor cubiti. This arrangement is rare. The direction of the fas- 
ciculi more commonly differs from that of the whole mass, and they 
descend more or less obliquely from one of the two tendons between 
which the belly exists to the other. We do not consider here if, as in 
the semi-penniform muscles (musculi semipennali, pennati simplices), 
for instance in the flexors of the hand and of the foot, of the fingers and 
of the toes, one of the tendons, usually the upper, be attached to the 
bone all its length and all that of the muscle ; or if, fixed by a point 
only at its upper extremity, and descending along the belly to the 
fibres to which it gives rise, it be loose in all its extent, as is seen in 
the semi-membranosus muscle. In both cases most of the muscular 
mass is placed on both sides between two tendons. In the first case, 
however, the direction of the fibres of the upper tendon is the same as 
that of the muscular fibres, while in the second case it is different. 

§ 341 . The forms of the muscles, in regard to the proportion of the 
three dimensions, differ much from each other, giving rise to a division 
of the muscles into the long, the broad, and the short, 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 281 

§ 342. The long muscles are found principally in the extremities, 
and are more or less cylindrical. Usually their tendons are large, and 
often much longer than their fleshy portion. Sometimes, however, the 
contrary is the case : thus, the tendons of the lumbricales are very 
short. In their course they often pass over several bones placed after 
one another. They form several layers, of which the superficial are 
the longest, and the deep muscles the shortest ; usually, these last 
are not extended except between two adjacent bones. Thus, for 
instance, the biceps cubiti is longer than the brachialis internus ; it 
extends from the scapula to the fore-arm, while the latter reaches only 
from the humerus to the fore-arm. It is among these muscles that the 
division into several bellies and the insertion by several tendons are the 
most frequent and apparent. They are even, especially at their upper 
part, so closely united in some regions, particularly the fore-arm, either 
by the aponeuroses which are extended over them, or because the 
fibres of one are inserted into the tendon of another, that they cannot 
be separated except by cutting them. Usually they are more bulging 
in the centre than at their extremities, because their fibres almost 
always extend obliquely from the upper to the lower tendon, so that 
their extremities do not contain all their fasciculi, but only the upper 
and the lower, while in the centre we find not only all the central but 
also a part of the upper and of the lower fasciculi. 

§ 343. The broad muscles are usually thin ; they are found around 
the cavities of which they alone constitute the parietes, at least in great 
part, or which they cover, and of which they take the form. Among 
the first are classed the broad muscles of the abdomen, and among the 
second, several muscles of the cranium, the frontal muscle, the tern- 
poral muscle, and most of the sphincters. Generally these muscles 
preserve a uniform breadth and thickness in all their course. They 
are usually simple ; they never terminate in long tendons, but in slips 
(dentaliones), which attach them to different parts. In some parts, as 
the chest and the abdomen, the broad muscles are placed over each 
other, and are somewhat alike in form and size ; sometimes the 
broad cover the long muscles, as in the back. 

There are muscles which very evidently make the transition from 
the broad to the long muscles, either because they unite the two forms 
in all their extent, or because they are broad in one point and elongated 
in another. Among the former are the sterno-hyoideus, the thyro- 
hyoideus, and the recti muscles of the abdomen ; among the second, 
the pectoralis major muscle and the latissimus dorsi muscle, which are 
narrower at their extremities, but at the same time increase very much 
in thickness. 

§ 343. The short muscles are usually as thick as they are broad 
and long. They are generally triangular or square, and are undoubt- 
edly the strongest of all, since none contain a greater number of fibres 
in a given space. They are found principally in the points where 
great force must be employed, because the general arrangement of the 
parts is unfavorable to their motions ; as in the temporo-maxillary arti- 
Vol. I. 36 



282 GENERAL ANATOMY. 

dilation, in the hip-joint, in the vertebral column, and even partially ill 
the hand and the foot. The glutaeus maximus muscle and the deltoid 
muscle make the transition from this to the preceding class, as the 
muscles of the hand and of the foot lead to the first. 

§ 345. In regard to texture, the muscles of animal life appear formed 
of fasciculi and of fibres, which are situated close to each other, but do 
not interlace. Their fibres generally extend from one tendon to 
another ; sometimes, however, they disappear sooner, and we are then 
unable to demonstrate that they are blended with the adjacent parts. 
Mucous tissue is very abundant in these muscles, and it is often so 
loose that it makes a compound muscle of a simple one, because it 
divides it into several heads, which are implanted in a common tendon, 
and which are united by a large layer of mucous tissue, as is seen in 
the pectoralis major muscle. The mucous tissue usually exists more 
abundantly in the broad muscles ; hence their fasciculi are less com- 
pact than those of the other muscles. Almost all the nerves of these 
muscles arise from the brain and the spinal marrow only ; and even 
where there are filaments of the great sympathetic nerve, as in the 
neck, nerves are received also from the nervous system of animal life. 
The nerves often come from remote parts of the spinal marrow, 
although the great sympathetic nerve is the nearest source, as is seen 
in the diaphragm. The muscular system of animal life generally re- 
ceives more nerves but fewer blood-vessels than that of vegetative life. 

§ 346. The muscles are the powers which act, upon the bones or 
analogous organs, to remove weights. The bones are levers, and 
usually simple levers of the second class, in which the power, viz. the 
muscle, is placed between the point of rest, one extremity of the 
bone, and the resistance, the other extremity of the bone with the parts 
which are attached to it. The arrangement is not the same in all ; but 
generally speaking, it is in a manner more or less unfavorable ; so that 
to produce their effect, the muscles have to employ a force greater than 
would be required if the relation between the power and the resistance 
were more favorable. Hence the muscular force is very considerable. 
This law may be called the law of Borelli, because until the time of 
this physiologist, the contrary opinion was admitted, and it was main- 
tained that the muscles are arranged to raise the heaviest burdens by 
employing the least possible force. 

The circumstances which demonstrate that in general the arrange- 
ment of the muscles is unfavorable are, 

1st. Thcyare inserted near the fixed point. Almost all the muscles are 
attached nearer to this point than to the resistance. When then a 
weight is raised which is farther from the resistance than the insertion 
of the muscle, power employed by the muscle is greater in propor- 
tion to the difference between its distance from the fixed point and the 
distance between the latter and the weight : it is always greater than 
the weight of the burden. 

2d. The obliquity of the muscles in regard to the bones, or of the 
muscular fibres in regard to the tendon. Few muscles are attached to 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 283 

the bones at right angles, the most favorable of all for the employment 
of force ; most of them are inserted at very acute angles. On the other 
hand, in almost all the muscles the direction of the fleshy fibres varies 
more or less from that of the tendinous fibres. In regard to the first 
circumstance, the loss offeree is greater in proportion to the obliquity 
of the angle of the insertion of the muscle in the bone ■ as to the 
second, the loss which results from it is proportioned to the obliquity 
of the muscular with the tendinous fibres. 

3d. The resistance ivhich the muscle opposes to the bone on which it 
takes its fixed point. This bone, in fact, tends to extend it as much 
as does the weight raised by its effort, because the muscle contracts 
from its two extremities towards its centre. 

4th. The resistance of the antagonists over which it must prevail. 

5th. The friction caused by the parts which surround the muscle 
although it is diminished by the looseness of the mucous tissue which 
envelops it in all parts. 

But, notwithstanding all these circumstances usually unfavorable to 
the muscle in relation to the weight it ought to raise, there are others 
which diminish the loss offeree occasioned by them. 

Thus, the angle by which the muscle is attached to the bone is con- 
siderably increased, 

1st. By the swelling of the extremities of the bone on which the 
muscle passes. 

2d. By the extension of the ridges in which they are inserted. 

3d. By the formation of special small bones, which develop them- 
selves in the substance of the tendons, at a little distance from their 
insertion (§ 306). 

4th. By the direction that the parts give to the muscles, or only 
their tendons, near their termination ; they change their direction 
from oblique to perpendicular. It often happens that the angle of 
insertion of the muscle enlarges during the motion itself, and that' from 
a very acute it becomes almost a right angle. This is observed both 
in the muscles which act and in their antagonists. As to the friction 
it is diminished by the fat which accumulates between the muscles and 
between their fasciculi, and by the presence of fibrous organs, the 
sheaths, which give to the muscles and their tendons a determinate 
situation and a fixed direction. 

The loss of force which necessarily results from the obliquity of the 
fibres is amply compensated by their great increase in number ; for, 
in equal spaces, the more oblique the direction, the more numerous are 
the fibres, and, other things being equal, the power of the muscle is in 
direct ratio with the number of its fibres. 

Besides, in contracting, the oblique fibres shorten the muscle much 
more than the straight fibres. It requires less effort then to bring to- 
gether two fixed points by oblique muscles than it does by straight 
muscles, more particularly as often, for instance between the ribs, two 
oblique muscular layers which intercross, by acting diagonally, take 
the place of a single straight layer. This arrangement of the force 
diminishes the lassitude arising from muscular motion. 



284 GENERAL ANATOMV 

For the same reason, when the muscular fibres are oblique, motion 
takes place more quickly than when they are straight. 

Finally, when two intercrossing layers of oblique muscular fibres act 
on the same part, the motions admit of greater variety, since possibly 
the two layers contract at a time or only one of the two acts, and both 
employ an equal or different force. 

C. OF THE MUSCLES OF VEGETATIVE LIFE- 

§ 347, The muscles of vegetative life differ from those of animal 
life. 

1st. In respect to their mass. This is less, for they form but a trifling 
part of the organism even when we refer to them all the parts which 
have a slightly muscular structure. 

2d. In respect to their external form, This is much more simple 
They always form cavities which are lined by the internal membrane 
of the organs which they tend to compose. They are found in the 
vascular system, the digestive apparatus, the uterus, and the bladder, 
of which they form the muscular coat. Except in the heart, they have 
no appearance of tendons, because their action does not tend to displace 
the solid parts of the organism, but to expel fluids contained in the 
cavities they circumscribe. When tendons are seen, as in the heart, 
they are attached to parts which change their position by the contrac- 
tion of the portions of the organ to which the opposite extremities are 
attached. The annular muscles of animal life also present something 
analogous, for we can always figure them as the commencement of a 
canal, or rather as a dilated canal, the fibres of which would pass, not 
behind, but over each other. But these latter, both by their situation 
and their functions, make the transition from the muscles of animal 
to those of vegetative life : for the sphincters of the mouth and anus 
are placed on the limit of vegetative and of animal life, and the orbicu- 
laris palpebrarum muscle is less subject to the will than the other 
muscles of animal life. 

3d. In regard to their texture, they differ in several ways : 

a. In the general arrangement of their fasciculi, fibres, and filaments. 
These are not distinct and parallel to each other, as in the muscles of 
animal life, but interlace continually, and for this reason are much 
shorter than the fibres of the voluntary muscles. 

b. Their fibres are arranged in several superimposed la3'ers not only 
in those parts where nearly the same direction is followed, but where 
they proceed in opposite directions. 

These layers are most generally transverse or oblique, and form 
rings around the cavities they circumscribe. These rings are always 
stronger than the fibres which extend in other directions : they are 
nearest each other at the orifices of the cavities and form internal 
layers : they constantly surround the internal cavities, while frequently 
the other layers are evident only in some parts of their circumference, 
as for instance in the large intestine, and are deficient in a con- 



OF THE MUSCULAR SYSTEM IN THE NORMAL STATE. 285 

siderable extent, as in most of the venous system. Sometimes longi- 
tudinal fibres are found without annular fibres, as in the large veins. 
These two directions are the most usual, and also exist together most 
frequently. 

c. There is less of mucous tissue in the muscles of vegetative life. 

d. Their texture presents greater differences in different parts. 
There is more difference in color, cohesion, and situation, between the 
fibres of the heart, the arteries, the veins, the intestinal canal, and even 
between the different parts of the intestinal canal, the uterus, and the 
bladder, than is found in regard to size and external form between those 
muscles of animal life which differ the most from each other. 

The heart is very red, redder than the muscles of animal life, as solid 
as they are, but more compact, and very thick in proportion to its 
cavity : its internal face is very unequal and reticulated, and it is com- 
posed of several superimposed layers. The fibres of the arteries are 
hard, brittle, flat, and yellowish, and all follow precisely the same di- 
rection. Those of the veins are redder, softer, and directed the contrary 
way, and are visible only in the large trunks. 

The muscular fibres of the intestinal canal are of a pale red, and 
very soft. 

In the esophagus and in most of the alimentary canal, we find only 
two layers of fibres ; in the stomach are three. Their thickness is not 
proportional to the size of the cavity. 

The fibres of the bladder are pale and form a much more complex 
tissue than in the other organs. 

The fibres of the uterus are very indistinct, except during pregnancy, 
and even then they are pale and hardly visible ; and, with the arterial 
fibres, are, of all we have mentioned, the most unlike the muscles of 
animal life, to which the fibres of the heart bear the greatest resem- 
blance. 

e. Have the fibres of the muscles of vegetative life more power of 
resistance than those of animal life, as Bichat asserts, because that 
ruptures of the hollow muscles are rare, however greatly they may be 
distended, while many examples have occurred of ruptuies of the volun- 
tary muscles ? Is it a fact that the muscles of vegetative life are rarely 
ruptured, while this often occurs in those of animal life ? We think 
precisely the contrary. Bichat states that we find many instances on 
record of ruptures of the diaphragm, while rupture of the stomach, the 
intestines, and the heart, are not known. If we wish to arrive at an 
exact result, we must not compare a muscle, which, from its situation, 
form, and functions, is unable to support a violent shock, with other 
muscles on which this cause cannot act directly ; we should consider 
the two systems in the same circumstances. But — will a volun- 
tary muscle tear more readily than a muscle of vegetative life, when 
slowly and gradually distended 1 We think not. The muscles of animal 
life frequently become thin membranes from the pressure of large tu- 
mors without being ruptured ; they resist the powerful efforts of their 



286 GENERAL ANATOMY 

antagonists, while a mechanical obstacle not unfreqnently causes the 
rupture of the muscles of vegetative life. 

4th. In the arrangement of their nerves and vessels. They receive 
fewer nerves but more vessels than the muscles of animal life. Their 
nerves except those of the esophagus, the stomach, and the bladder, 
are derived for the most part from the great sympathetic nerve. 

5th. The muscles ofvegetative life have no antagonists. Their function 
is to contract and shorten the canals and cavities they surround. Hence 
the substances within these cavities are usually considered as then- 
antagonists. The different layers of which they are composed are not 
opposed in action, but on the contrary by acting in concert, they execute 
their function better, viz. that of diminishing the size of their cavities. 
The action of some layers does not interfere with and prevent that of 
others : a kind of opposition is, however, more or less evident between 
the different regions of the muscular layer of the same organ of vege- 
tative life. Thus the fibres of the ventricles of the heart always con- 
tract alternately with those of the auricles, as those of the arteries 
alternate with those of the ventricles : the greatest activity of the fibres 
of the auricles is attended with the greatest degree of inaction in the 
ventricles, exactly as is seen between the antagonist muscles of animal 
life. There are regions in the intestinal canal where the antagonism 
is but temporary, between which are no distinct limits, and which are 
not marked by differences of structure, for they are adjacent portions 
which alternately dilate and contract to expel the substances contained 
in this-tube. 

6th. The muscles of vegetative life act, at least part of them, sooner 
than those of animal life. This is true, especially in regard to the 
heart and the alimentary canal. As certain parts, at least of the heart, 
preserve their irritability longer than all the other muscles, after the 
extinction of the mind, (§ 327,) we may sa}', in general, that irritability 
continues longest in the muscles of vegetative life, although there are 
some of the muscles of animal life which remain irritable longer than 
some of the involuntary muscles. 

7th. The muscles of vegetative differ from those of animal life in the 
relation between them and the stimulus which causes them to act. 
This relation is of two kinds : 

a. The muscles of which it treats are more or less influenced by the 
modifications of the spiritual principle. The will has rarely any influ- 
ence upon many of them, as the heart,(l) and perhaps never has 
any if we except some cases which may be otherwise explained. Its 
influence on others, as the bladder and the rectum, is very feeble, and 
their actions as caused by the will are very slow. On the contrary, 
the changes which take place involuntarily in these muscles cannot 
be arrested by the will. Hence why their motions are not changed, or 
but in a slight degree, in states which arc marked by a total inaction 

(1) This, however is the case in an Englishman, mentioned by Cheyne, and (hat 
of Bayle, as reported by Ribes, who could at pleasure relax or suspend the motions 
of the heart (?) F. T. 



OP THE MUSCULAR SYSTEM IN THE ABNORMAL STATE. 287 

of the intellectual principle, and during which the muscles of animal 
life are at rest. 

b. The stimuli which act on them are always separated from the 
muscles by an intermediate substance, as in the intestinal canal and 
the bladder by the mucous membrane, in the vascular system by the 
internal membrane of the vessels, &c. But this difference is not en- 
tirely absolute, for we find an arrangement very analogous to it in the 
voluntary muscles, inasmuch as their nerves which are the conductors 
of the different changes supervening in the central parts of the nervous 
system, in virtue of which the muscles contract, are also separated 
from the proper muscular substance by the mucous tissue which en- 
velops them. 



ARTICLE SECOND. 



OF THE MUSCULAR SYSTEM IN THF. ABNORMAL STATE. 

§348. The muscular substance when once destroyed is never re- 
produced, and wounds of the muscles, where there is no loss of sub- 
stance, heal in the same manner as those where the substance is de- 
stroyed. These two states are very similar, from the separation which 
the contractions of the two portions of the muscle cause between the 
edges of the wound. In both cases the opening is always a deep 
point, around which the edges of the wound in the muscle are some- 
times swelled. It fills at first with a vascular, reddish, soft, and gelati- 
nous mass, which afterwards loses its vessels and becomes yellowish 
white, harder, and horny, and always insensible to the action of stimu- 
lants, whatever they may be. We sometimes, but not often, find in 
this mass, several months after the wound, traces of irregular fibres, 
but slightly analogous to muscular substance, and when the muscle has 
been entirely divided, its portions are so completely separated that the 
irritation of one part causes no contraction in the other.(l) Still, how- 
ever, notwithstanding this insulation, both continue to be nourished, 
and they do not waste, as happens to a nerve which has been cut ; 
doubtless because the muscles, unlike the nerves, do not form an unin- 
terrupted organized system. A muscle which has been transversely 
divided and has cicatrized, is in fact changed into a double-bellied mus- 
cle, and resembles those which have tendinous intersections. 

§ 349. The muscles present anomalies in form, chemical composi- 
tion, and in action. We shall here examine only the first two. 

(1) Kleemann, Diss, sistcns quozdam circa productionem, par Hum corporis humani, 
Halle, 1786, exp. ii.— Murray, Commentatio de redintegratione partium corporis 
humani nexu suo solutarum vel amissarvm, Gottingen, 1787, exp. i-x. — Huhn, De 
regeneratione partium, Gottingen, 1787.— SchneU, De natural reunionis muscidorum, 
vwneratorum, Tubingen, 1804. 



288 GENBRAL ANATOMY. 

§ 350. Among the deviations of formation,( 1 ) which are usually 
primitive, we class : 

1st. Anomaly in number. This is almost always congenital. 
Sometimes all the muscles of the whole body or of a whole limb are 
deficient, although the other parts are formed ; but this occurs only 
when the whole body is incompletely developed, and particularly when 
its upper part is not formed and there exists in its place a gelatinous 
mass. In many cases of this kind some mistake may have arisen in 
regard to the muscles, because they are then usually very white, and 
an enormous quantity of liquid is found accumulated under the skin. 
It is more frequent that some muscles are either wholly or partially 
deficient, so that for instance they are not attached to the solid parts as 
extensively as usual. The muscles most frequently absent are those 
of small size, the functions of which are trivial and may be supplied 
more or less by others, as the palmaris brevis, the plantaris, the pyra- 
midalis, and the zygomaticus minor muscle, and some fasciculi or 
heads of the flexors of the fingers or toes. 

Supernumerary muscles are rarely found. (2) The enlargement and 
the multiplication of slips of insertion gradually leads to this anomaly, 
which exists in some muscles rather than in others : thus we see it often 
in the recti muscles of the abdomen, the small muscles of the head, the 
biceps femoris, and less frequently in the biceps flexor cubiti. It is not 
uncommon in the latissimus dorsi, the pectoral muscles, the indicator 
muscles, and the extensor proprius minimi digiti. Among the su- 
pernumary muscles thus developed, we distinguish the sternalis mus- 
cle, a proper extensor of the third toe, &c. We must here remark, that 
one limb resembles another in this respect, that the anterior portion of 
the body is regulated by the posterior, and that these anomalies almost 
always are analogous with the structure of some animal. (3) 

2d. An unusual largeness or smallness in the size of the muscles is 
seldom congenital ; they commonly develop themselves accidentally. 
When muscles are abnormally small, it results from the want of exer- 
cise. Compression even destroys some muscles entirely. An unusual 
degree of power in these organs, often but not always, results from 
their being used. It becomes morbid only when a muscle, for instance 
the heart, performs its functions so powerfully as to injure the general 
health. 

(1) Heymann, Varietates prcec. corp. hum. muscul., Utrecht, 1784. — Brugnonc 
Observations myologiques, in the M6m. de Turin, vol. vii. p. 157-191. — Roscnmuller, 
De nonnullis muse. corp. hum. varietat., Leipsic, 1804. — Gantzer, Diss. anat. mus- 
cul. variet. sistens, Berlin, 1813. 

(2) Tiedemann having found the pectoralis, major and minor, the glutaei and the 
trapezii muscles double in the same subject, concludes, that great power in man is 
not always the result of exercise, but sometimes depends on the congenital redun- 
dancy of several large muscles. (Deutsches Archivfiir die Physiologic) The author 
of this treatise was led to form the same opinion from another example of the same 
kind, and he concludes from sufficient facts, that contrary to the opinion of Tiede- 
mann, this anomaly of the muscular system happens usually on both sides at once, 
as Bichat has said. 

(3) J. P. Meckel, De duplicitate monstrosa, Halle, 1715, § 42. 



OP THE MUSCULAR SYSTEM IN THE ABNORMAL STATE. 289 

3d. The muscles sometimes present primitive anomalies in their at- 
tachments. Not reaching then their accustomed points, they remain 
powerless, or act contrary to what they ought naturally. 

4th. Anomalies in connection are usually accidental. They are 
either confined to the muscle or extend to its relations with the adja- 
cent parts. We have already described (§348) the phenomena which 
attend wounds of the muscles. We not unfrequently find a rupture 
of whole muscles or more commonly of some muscular fasciculi, an 
effusion of blood around the rent, and this although there is no exter- 
nal injury. These ruptures(l) probably depend on the spasmodic con- 
tractions which supervene in the late moments of life. But sometimes 
the loss of substance is consecutive to the effusion of blood. Continual 
pressure may also destroy some part of a muscle, and in this manner 
interrupt the connection which exists between it and the others. (2) 

The displacements of the muscles in regard to the adjacent parts, 
usually result from adhesions which the organs contract after violent 
inflammation. This inflammation may also cause the adhesion of the 
muscular fasciculi to each other, which is accompanied with a greater 
or less degree of rigidity. The luxation of the muscles may also be 
referred to this cause. (3) . 

§ 351. Among the alterations in the texture of the muscles we must 
place first the anomalies they offer in their degree of cohesion ; they 
are sometimes extremely flabby and brittle, and again on the con- 
trary more elastic and firmer than usual. The former state is ob- 
served in feeble men and in asthenic diseases ; the second is independent 
of every other morbid state, and occurs most frequently in the hollow 
muscles, as the bladder, and especially the heart. The color of the 
muscles sometimes varies from its natural shade, although their texture 
in other respects is not sensibly altered. Thus in certain cases the 
muscles are unusually pale. This state most frequently attends 
paralysis, brittleness, and flaccidity of the muscles. The same anomaly 
of color is observed also in dropsy, where the interstices of their fasci- 
culi are filled with serum and not with fat. Under these circumstances 
the substance of the muscle wastes considerably. 

So likewise in rheumatism, which generally attacks the sheaths of 
the muscles, we almost always find a gelatinous fluid effused between 
these sheaths and the surface of the muscle. 

The paleness and softness of the muscles form the transition to an 
altered texture of these organs which is unfrequent, and which some- 
times constitutes a primitive deviation of formation in supernumerary 
limbs, and sometimes supervenes to inaction of the muscles : we mean 
their change into fat, either preserving their texture or losing it entirely, 

(1) J. Sedillot, Memoire sur la rupture musculaire ; in the Mem. ct Prix de la soc. 
med. de Paris, 1817. 

(2) Lieutaud, Hist. anat. med., Paris, 1767, vol. ii., p. 329. 

(3) J. Hausbrand, Diss, luxationis sic dictce muscularis refutationcm sistens, Ber- 
lin, 1814. This dislocation admitted by Pouteau, Portal, and others, can take place 
only when the enveloping aponeuroses are divided ; but Hausbrand has gone too far in 
saying it was absolutely impossible. F. T. 

Vol. I. 37 



290 GENERAL ANATOMT. 

and finding in them cellular tissue filled with fat.(l) All the parts of 
the muscles then generally become smaller than they are in the normal 
state. (2) 

The sleatomatous tumors are developed between the fasciculi of the 
muscles less frequently. 

The accidental formation of bone(3) and the tuberculous, schirrous, 
or fungous formations in the muscles are still more rare. 

The appearance of hydatids in the mucous tissue which separates 
the fasciculi of the muscles is a phenomenon a little less rare. We 
have found it in the voluntary and involuntary muscles, and among the 
last principally in the heart. 

§ 352. It rarely or never happens that the muscular substance is 
accidentally developed. In fact, sarcoma has been placed in parallel 
with the muscle, (4) it has been pretended that the serous membranes,(5) 
and even the bones(6) have been changed into muscular substance, 
and finally, that this substance has been found in the ovaries. (7) But, 
undoubtedly in pointing out alterations of texture, the distinctive cha- 
racters have been neglected to attend only to their analogies. 



SECTION IX. 



OF THE SEROUS SYSTEM. 



GENERAL REMARKS ON THE SEROUS SYSTEM. 
A. ITS NORMAL STATE. 

§ 353. The serous system is very well marked both in form and tex- 
ture, although in more than one respect it seems to be but a slight mo- 
dification of the cellular tissue. It is not a connected system, but it 
exists in all parts of the frame and assists in uniting different organs. 
We may refer to it the synovial membranes, or the articular capsules, 
which in structure and functions do not differ from it, and hence divide 
it into the proper serous system and the synovial system. 

(1) Beclard does not admit this change into fat, and thinks that the error arises 
from simple appearances, and that the muscular fibres are only discolored. This 
opinion is contradicted by well established facts. F. T. 

(2) Gay Lussac in the Annales de chimie ct dc physique, vol. iv., p. 71. 

(3) Tiedemann relates a case of accidental bony concretions which were very 
abundant in several muscles of a man affected with grout, (Deutsches Archivfur die 
Physiologie, vol. v., p. 355.) These concretions were attended with the ossification 
of several arteries. They were composed of the phosphate and a small portion of the 
carbonate of lime, and of one fifth of animal matter, without any appearance of pro- 
per org-anization. F. T. 

(4) Fleischmann, Leichenocffnungen, 1815, p. 112. 

(5) Dumas, in Sedillot, Rccueil periodique, vol. xxv., p. 74. 

(6) Colomb, (Euvrcs chirurg., p. 72. 

(7) Dumas, Med. eclair., vol. ii. 

(8) Bichat, Traitedes membranes, Paris, an viii., p. 78-111 and 202-292. 



OP THE SEROUS SYSTEM IN THE NORMAL STATE. 291 

§ 354. This system always assumes the membranous form. It is 
composed of a certain number of round sacs, which are entirely distinct 
from each other, and are usually perfectly closed. 

The form of these sacs is not every where the same. They may 
be divided, in this respect, into two large sections. The first compre- 
hends the simple sacs, which present in all parts a rounded surface. The 
serous membranes, which in part compose this section belong to the 
synovial system ; they are always placed between the tendons and 
the bones, and are badly termed the bursal, mucosa. These bursae 
cover only one part of the tendon under which they are found. The 
serous membranes of the second division are more complex in their 
forms, and seem composed of two sacs, one of which is found within 
the other. It appears like a simple sac, folded on itself in a portion 
of its circumference, or strengthened in part in its proper cavity by 
the action of a foreign body ; if this body be removed, or, what may be 
done in some places, if the turned portion of the serous membrane be 
detached and the latter be thus insulated, we obtain a single round sac. 
In the normal state, the external and the internal sacs do not commu- 
nicate nor touch, except where the sac seems to be reflected on itself. 
Further, the external sac always forms a much larger cavity than the 
internal, although, in several serous membranes, the latter is more ca- 
pacious than the former, because the membrane has so many folds. The 
following are all the proper serous membranes, which are found in the 
normal state, viz. the tunica arachnoidea, the pericardium, the pleura, 
the peritoneum, the tunica vaginalis testis, the synovial membranes, and 
several bursas, mucosae. All these membranes form perfectly closed 
sacs ; the part turned in always incloses an organ to which it adheres 
intimately ; in the serous membranes this organ is generally a viscus ; 
the synovial capsules generally inclose the extremities of two adjacent 
bones which move upon each other ; and finally, the bursas mucosae 
which belong to this section contain a part of a tendon. The adhesion, 
which is slight where the membrane is reflected upon itself, becomes 
more and more intimate, and often increases so much that, as in the 
testicles, the spleen, the lungs, and all the articular extremities of the 
bones, it is impossible to separate the serous coat from the parts be- 
low, except to a slight extent ; while, in all the other parts the inner 
sac is in fact blended with them. 

This adhesion is not equally intimate in every part. Thus, for in- 
stance, the peritoneum adheres but feebly to those parts of the bladder, 
of the duodenum and of the pancreas which are covered by it, rather 
more to the viscera of the digestive apparatus, and very firmly to the 
internal organs of generation in the female. Generally the harder the 
parts to which the serous membrane is connected, the more firm is its 
union. This proposition applies to the external portion of the serous 
membrane as well as to its reflected portion. The glands and mus- 
cles are separated from it with facility, but the fibrous organs and the 
cartilages with great difficulty. 

§ 355. The serous membranes are reflected directly upon them- 
selves, so that the internal sac is closely applied upon the organ it 



292 GENERAL ANATOMY. 

covers ; and between it and this organ there is a depression of variable 
length formed by two folds, between which the vessels and the nerves 
proceed to the organs contained in the sac. We may mention, as in- 
stances of the former arrangement, several portions of the large inies- 
tine, particularly the ascending and the descending colon, a part of the 
liver and the heart ; all the small intestine, and the spleen are exam- 
ples of the second. In the former case a portion of the organ is most 
usually uncovered by the serous sac ; this is the case in the ascending 
and the descending colon, the upper and posterior portions of the liver. 
In the latter, but a small portion of the organ, the point where its ves- 
sels enter, is destitute of the serous membrane. These two arrange- 
ments are generally found in the same organ, as is the case with the 
peritoneum, where it covers the liver. 

Besides these folds which exist between the external and the inter- 
nal sac, and the organs covered by the latter, the serous membranes form 
others of a different character. They always extend bej^ond the or- 
gan covered by the internal sac ; but then sometimes they hang 
loosely and are again reflected on themselves ; sometimes they pass 
from one of the parts contained in the common external sac to an- 
other. The former arrangement is seen in the epiploon, the second in 
the external envelop of the round ligament in the ilio-femoral articu- 
lation, in the similar bands contained in the knee-joint, and in the second 
class of the tendinous bursse. However, when closely examined, all 
these processes are essentially the same, that is, they are all produced 
by the transition of the internal serous sac from one organ to another. 
In fact, the omenta differ from the tendinous bursa? only in being more 
extensive, so that they are obliged to fold upon themselves, when pass- 
ing from one organ to another. 

We however find in some places folds which are perfectly loose, 
and which arise from the surfaces of the organs lined by the internal 
sac ; such are the appendices epiploicee of the large intestine, and the 
prolongations which in many capsules of the joints, for instance, those 
of the knee- and hip-joints, cover the glands of Havers. 

§ 356. The folds and prolongations of the serous membranes are 
usually connected with the respective situation of these membranes, and 
of the organs which they cover. In fact, in certain circumstances they 
cover organs, which they do not cover when these circumstances 
vary. Thus, the intestines, when filled and distended, are imbedded in 
the mesentery, the stomach in the omentum, and the impregnated 
uterus in the broad ligaments. 

The serous membranes differ, in fact, from the structure of the organs 
they cover, and they must be considered only as drawing a more exact 
line of distinction between these other organs, in respect either to situa- 
tion alone, or to their mode of existence. Thus they envelop the most 
important organs : the brain, the spinal marrow, the lungs, the heart, 
the intestinal canal, and the principal parts of the genital apparatus. 

Hence why their diseases have less effect upon the organs covered 
by them than those of other membranes. In dropsies, in thickening, 



OF THE SEROUS SYSTEM IN THE NORMAL 6TATE. 293 

and ossifications of the serous membranes, the subjacent organs are 
perfectly healthy, even when they adhere intimately, as in the testicle. 
Still, whenever the union is such that the membrane and the organ are 
one, as in the capsules of the joints, the diseases of the former soon 
affect the latter. For the same reason, a part of the the peritoneum 
not only abandons certain organs in the circumstances above mentioned, 
but leaves without inconvenience the parietes of the abdomen either ab- 
normally, as in hernia, or naturally, as in the descent of the testicles 
into the scrotum. We must not forget however that, in the cases 
above examined, there is an alternate -separation and reunion of the 
organs with the serous membranes, but also a distension and contrac- 
tion of the same organs. 

§ 357. The serous membranes, even those which have a complex 
form, are perfectly closed, although at first view they seem to be per- 
forated, yet they only fold upon themselves and are perfectly closed. 
There is but one exception to this rule, viz. the abdominal orifice of the 
fallopian tubes, which open into the peritoneal cavity on each side. 
This too is the only instance where a serous membrane is continuous 
with a membrane of a different class, which, in this case, is a mucous 
membrane ; for we cannot mention as such the communications which 
exist between the different parts of a serous membrane, as the external 
arachnoid membrane and that which lines the cerebral ventricles, be- 
tween the great cavity of the peritoneum and that of the omenta, &c. 
This complete closure of the serous membranes explains why the con- 
gestions of serum never extend beyond the limits of their cavities in 
dropsy of the pericardium, of the pleura, of the peritoneum, and of the 
tunica vaginalis testis. 

§ 358. The internal face of these sacs in the normal state is always 
smooth, the external is rough, and united to the adjacent parts by mu- 
cous tissue, at least most generally, although there are several excep- 
tions ; for instance, both faces of the lower portion of the arachnoid 
membrane are loose. In fact, in the serous membranes of the second 
class, the external face of the internal sac which looks toward the 
inner face of the external sac is smooth and loose, while the internal 
face is uneven and attached ; but this arrangement does not contradict 
the law we have established, since the internal sac is only a reflected 
portion of the external. The smoothness of all the organs which exist 
in serous membranes comes only from the internal sac ; when detached, 
they seem rough and covered with mucous tissue, and their surfaces 
are never smooth in those parts where, in the normal state, the serous 
membranes do not cover them : such is the liver in several places, the 
posterior face of the ascending and descending colon, most of the pos- 
terior part of the rectum, a large portion of the uterus, of the blad- 
der, &c. 

These sacs are always thin in proportion to their other dimensions, 
but there is never a direct and constant relation between their thickness 
and their capacity. They are always more or less transparent, white, 
and shining, but less so than the fibrous organs with which they are inti- 



294 GENERAL ANATOMY. 

mately connected. Thus the arachnoid membrane lines the internal 
face of the cerebral and of the spinal dura mater ; the pericardium is 
covered by a fibrous membrane, and when this is deficient it is supplied 
by the tendinous part of the diaphragm : the pleura is situated under 
the periosteum of the ribs and the tendons of the intercostal muscles ; 
the tunica vaginalis testis is placed under the tendon of the cremaster 
muscle ; the synovial membranes under the fibrous ligaments and upon 
the periosteum of the bones. 

§ 359. The whole serous system appears to be but a slight modifi- 
cation of mucous tissue, but of a mucous tissue more dense than usual, 
and coagulated in larger layers. This is seen from the following con- 
siderations : 

1st. From its external appearance. Both have the same color. If 
the mucous tissue be inflated with air, cells are produced which cannot 
be distinguished from the serous tissue, especially from its thin portion, 
as the peritoneal coat of the intestines, the epiploon, the arachnoid 
membrane, &c. So too the fibrous membranes may be converted into 
mucous tissue by maceration, and by inflating air into the subjacent 
cellular tissue. 

2d. It is not unfrequent to find simply mucous tissue filled with 
synovial fluid in the place of certain parts of the synovial system. 

3d. The serous membranes, like the mucous tissue, present a homo- 
geneous mass : we see no trace of fibres. 

4th. Like the mucous tissue, they receive few blood-vessels, so that 
they are composed almost entirely of absorbent and exhalent ves- 
sels^ 1) Mascagni thinks them formed only of absorbents, because 
mercury injected into the lymphatic system converts them into a tissue 
of these vessels ; but when the blood-vessels are injected, or when in- 
flammation, attacking the serous membranes, fills the capillaries with 
blood, the serous system becomes a tissue of blood-vessels. In fact we 
find numerous and considerable blood-vessels on the external surface 
of these membranes, but they do not enter into their composition. 
The arachnoid membrane is entirely destitute of vessels. The serous 
membranes when exposed in a living animal are colorless, and blood 
does not issue from them when they are divided after death. 

5th. Like the mucous tissue they are destitute of nerves. 

6th. 'The functions of the mucous tissue and of the serous mem- 
branes are the same, viz. exhalation and absorption. (2) Like the mucous 
tissue, the serous membranes form around the parts they envelop a 
perfect limit, and which is more marked in them on account of the great 

(1) This is not the opinion of Rudolphi. He says that the serous membranes have 
no vessels, and that they may be easily detached from the organs which they cover, 
especially when there is a dropsical state. If we then examine them with a micro- 
scope there are no traces of vessels. They are formed only of cellular tissue, of which 
they constitute the bounds to free surfaces. Ribes has ascertained the same fact by 
numerous dissections. F. T. 

(2) According to Rudolphi they do not secrete, but only allow the perspiration 
furnished by the cellular tissue to pass through them, fulfilling in respect to it the 
same duty performed by the epidermis in regard to the perspiration of the 6kin. Nor 
does he admit that they are porous. F. T. 



OF THE 8EROUS SYSTEM IN THE NORMAL STATE. 295 

importance of these organs. As all the organs are imbedded in mucous 
tissue, which is the common organ of nutrition and formation, so the 
envelops of the fetus in structure and functions resemble serous mem- 
branes exactly. We may then call them the formative membranes, as 
the mucous tissue has received the term of formative or generative 
tissue.* 

§ 360. The serous membranes possess a great degree of extensibility 
and of contractility : hence they remain uninjured even when greatly 
distended by dropsies or tumors. We must however remark, that, in 
such cases, they are not only distended, but their folds are partially de- 
veloped, and are a little displaced from the looseness of the mucous 
tissue which unites them to the adjacent parts, and that, they really 
increase in mass. Hence why, in dropsies for instance, instead of being 
thinner in proportion to the enlargement they have acquired, they are 
thicker. That the changes they experience result in great part from 
a forced extension is proved by the rapid and great diminution of their 
cavities, when the substances which distend it (for instance, the serum 
in dropsies) are removed ; and this diminution takes place without 
wrinkles or folds. 

The serous membranes, properly so called, possess these properties 
in a greater degree than the synovial capsules. The latter are torn 
when a great force acts upon them, as in dislocations ; the former are 
distended, as in hernia. We must not forget, however, that this differ- 
ence is mostly owing to the difference in the mode of connection with 
the subjacent parts. 

In the healthy state the serous membranes are insensible, or sensible 
only in a slight degree ; but they become highly so in diseases, and 
when they are inflamed the pain is very acute. 

§ 361. The functions of the serous membranes are, to insulate the 
organs they envelop, and to facilitate their motions, by rendering their 
surfaces smooth, and by exhaling a lubricating fluid, which, perhaps, in 
the normal state of the proper serous membranes, has the form of vapor, 
but is liquid in the synovial system. Both resemble strongly, in their 
essential properties, the serum of the blood : that of the proper serous 
membranes differs but little from it : that of the articular membranes, 
called synovia, is very analogous to it, but differs from it as we shall 
mention hereafter. Both contain a large proportion of water, a little 
albumen, a gelatinous substance, and several salts.(l) 

§ 362. The serous membranes themselves differ in respect to their 
external form and their texture, but more in regard to the former than 
the latter. 

* Another point of resemblance between these tissues is the similarity of the dis- 
eases which affect them. On this point Prof. Horner remarks, ( Treatise on Gen. 
and Spec. Anat., vol. ii. p. 7,) " My own experience goes to prove that dropsy seldom 
manifests itself to any extent in the cellular tissue without also going to the serous 
texture and the reverse." 

(1) Hewson, On the properties of the lymph contained in the different cavities of the 
body, in Exper. inq., ii. ch. vii.— Bostock, in Nicholson, Journal, vol. xiv. p. 147. 



296 GENERAL ANATOMY. 

Have they originally the form of closed sacs ? This is probably not 
the case with all. We have every reason to think that the pericardium 
and the peritoneum are at first open, for, in the early periods of exist- 
ence, the heart and the viscera of the abdomen are uncovered, although 
it afterwards happens that the latter, exposed as before, are still co- 
vered by a prolongation of the peritoneum which accompanies them. 

The form of the serous membranes varies at different periods of life ; 
they disappear in some parts, and are developed in others ; these dif- 
ferences depend on the changes which supervene in the situation of the 
organs within their cavities. Thus the fold of the peritoneum which 
at first traverses the umbilical ring disappears in time, while another 
forms and engages itself in the inguinal ring, when the testicle begins 
to descend from the abdomen into the scrotum. Even the number of 
the serous membranes, considered as so many distinct sacs, varies at 
different periods of life. Thus the tunica vaginalis testis is at first a 
continuation of the peritoneum, bat sometime after birth the upper part 
is obliterated, and two separate cavities are formed, the peritoneal and 
the vaginal. 

The tissue of the serous membranes is more uniform ; except that, 
like all the organs, they are at first more loosely attached to the ad- 
jacent parts, whence they are more easily insulated in the early pe- 
riods of fife. This arrangement is not always applicable, except to 
their external fold : it does not extend, at least in all cases, to their 
internal and reflected layer. Thus we cannot detach the serous mem- 
branes from the tunica albuginea and from the articular capsules with 
greater facility in the fetus than in the adult. 

The characters of the fluid they exhale probably vary as do those of 
all others in the course of life, that is, it is thinner and more watery in 
youth than in advanced age. This conclusion is drawn from comparing 
the results of analyses made by Bostock and Hewson. The latter 
states the fluid to be albuminous and gelatinous, the former that it re- 
sembles fibrin. 

B. OF THE SEROUS SYSTEM IN THE ABNORMAL STATE. 

§ 363. The serous membranes present remarkable anomalies in form 
and in texture. The primitive deviations of formation are somewhat 
rare. They consist usually in the suspension of development — such as, 
1st, the absence of a portion of these membranes, especially the peri- 
cardium, the pleura, and the peritoneum, when the heart, the viscera 
of the thorax and abdomen are exposed ; 2d, the abnormal communi- 
cation between different serous membranes, the cavities of which are 
not properly united, except during the earliest periods of life. To this 
we refer particularly the communication existing between the tunica 
vaginalis and the peritoneum, when the canal between them is not 
effaced, and which is occasionally the cause of congenital inguinal 
hernia. 

But other primitive deviations of formation also occur. As, for in- 
stance, the existence of a serous sac within the proper sac, communi- 



OF THE SEROUS SYSTEM IN THE ABNORMAL STATE. 297 

eating with it by a more or less narrow opening, and inclosing a por- 
tion of viscus which is generally at liberty and which separates it from 
the rest. This phenomenon has been observed only in the peritoneum, 
and it is curious, as being essentially the abnormal repetition of a nor- 
mal formation. 

The serous membranes are liable to accidental deviations of forma- 
tion, as they take part in hernia. Here a portion of serous mem- 
brane generally detaches itself from the parietes of the cavity to which 
it adheres, passes across a separation which is naturally broad, or is 
enlarged by the action of an external cause, and thus forms a sac called 
the hernial sac, (saccus hernice,) into which penetrate some of the 
visceia lodged in its cavity and covered by its membrane. This latter is 
rarely torn, and the viscera seldom protrude unless preceded by it, and 
it is unfrequent for the hernia to have no sac ; this case happens only 
after great violence, and even then the hernia occurs only in certain 
places, for instance in the upper wall of the peritoneum. The her- 
nial sac also is rarely ruptured or opened by the effects of previous 
disease, so as to permit the viscera inclosed by it to be in immediate 
contact with the common integuments. The peritoneum only is sub- 
ject to these different accidents, because, of all the serous membranes, 
it adheres the least to the parietes of its cavity, and also because the 
parietes of the abdomen are less protected by the bones than those of 
the other two splanchnic cavities, and cannot resist the efforts of exter- 
nal agents so powerfully. 

The serous membranes are not unfrequently distended extremely by 
the fluid they exhale. This fluid often accumulates in very great 
quantity, and constitutes the different kinds of dropsy (hxjdrops.) Here, 
the animal substance is thin,and generally less abundant,so that the fluid 
of dropsy may be regarded as the serum of the blood, which has lost 
from two thirds to four fifths of its albumen ; however, the proportion of 
this substance is sometimes very much increased, doubtless, on ac- 
count of the absorption of the watery portion.(l) 

§ 364. The other changes in the forms of the serous membranes 
are, the results of morbid affections, and especially of inflammation, 
which often affects them. (2) Inflammation of the serous membranes 
tends to terminate by effusion into their substance which results in a 
thickening, or by effusion on their surfaces, which causes a mutual ad- 
hesion of the corresponding faces of the external and internal sacs, al- 

(1) Schreger, Fluidorum corporis animalis chcmiccc ^nosological specimen, Er- 
langen, 1800, p. 16-24. — Marcet, A chemical account of various dropsical fluids ; 
in the Edinb. med. and surg. trans. — Berzelius, On animal fluids; Med, chir. 
trans., vol. ii., p. 251-253.— Bostock, On the nature and analysis of animal fluids, 
ibid., vol. iv., p. 52. 

(2) Rudolphi maintains that inflammation is not situated in these membranes, 
hut in the organs they cover ; that they cannot inflame any more than the epidermis ; 
and that pleuritis, pericarditis, and peritonitis are inflammations of the surface of 
the lungs, heart, and abdominal viscera, &c. Chaussier and Ribes entertain simi- 
lar opinions. If serous inflammations be, in fact, only inflammation of the sub- 
visceral mucous tissue, we can conceive of the rapidity, the intensity, and the danger of 
these inflammations, and the abundant products they furnish. F. T. 

Vol. I. 38 



298 GENERAL ANATOMY. 

though the membrane is not destroyed by suppuration. These adhe- 
sions vary much in extent, solidity, structure, and number. Some- 
times they cover the whole surface of the serous membrane and the 
parts it envelops, so that it becomes almost impossible to distinguish 
the latter from each other, and one is induced to believe there is no ex- 
ternal sac; sometimes they are confined to one or a few points of the ex- 
ternal and internal sacs, whence only the organs situated in those places 
adhere. They may, too, become very intimate, even to a degree that 
where the united parts seem to make only one, or very loose and easily 
broken. Finally, the adhesions are sometimes very short, and some- 
times long ; in the latter case they form cords, ligaments, and mem- 
branes, termed generally false membranes (pseudo-membrance), which 
in nature more or less resemble that of the serous membranes, and 
which are often attended with fatal results, particularly when they are 
developed in very movable points or parts which may glide into the 
rings they produce, as in the intestines.(l) 

Farther, these adhesions probably take place only after inflamma- 
tion, and are never primitive, although Bichat admits the contrary in 
regard to some perfectly organized ligaments, often found between the 
external and the internal sac of the pleura, and which are evidently 
composed of two folds fitted to each other, and although Tioch(2) main- 
tains this opinion, in regard to some analogous ligaments situated be- 
tween the heart and the pericardium, because they resemble those pre- 
sented by the hearts of several reptiles in their normal state. It is cer- 
tain, at least, that the most perfect organization of these appendages 
is not sufficient to justify this opinion, because, parts which have a more 
perfect organization, as bones, teeth, and even whole serous mem- 
branes, are often developed by a vital act, which does not differ essen- 
tially from inflammation. 

We do not observe the same form in all the alterations in texture of 
the sero; s membranes which result from inflammation, ond are charac- 
terized by the thickening of their substance. Thus, in the internal sac 
of the pericardium, broad smooth layers appear, which are termed 
macules, cordis, and in the peritoneum numerous small, hard, round ele- 
vation ' very analogous with the miliary eruption. 

§ 365. The serous system tends much to ossify, and in this relation 
presents the same differences as in that of adhesion. Sometimes, in 
fact, the substance of the membrane ossifies ; sometimes smooth anl 
usually round bodies, varying in number and size, form on its sur- 
face, these are more or less loose, and are often entirely detachel 
from the membrane and float freely in its cavity. These phenomena 
are common to all the serous membranes, although found in some more 
frequently than in others. Tin s, that portion of the peritoneum which 
covers the spleen, is, of all others, the most disposed to ossify ; next 
comes the internal sac of the tunica vaginalis testis ; the others, except 

(1) Villerme, Vraite desfausses membranes. Paris, 1814. 

(2) Mem. dc Montpellier, vol. ii, p. 351. 



OP THE SEROU8 SYSTEM IN THK ABNORMAL STATE. 299 

the tunica arachnoidea which rarely ossifies, differ little from each 
other in this respect. 

These accidental ossifications almost always have the form of broad 
layers and often become, especially in the spleen, very laro-e so that 
even the proper substance is frequently entirely concealed The syno- 
vial membranes ossify less frequently; still, however, as their internal 
sac identifies itself with the articular cartilages, we may say that they 
become cartilaginous even in their normal state, and that ossification of 
the proper serous membrane is only an abnormal repetition of the nor- 
mal state of the synovial membrane. 

It is not uncommon to see developed in the substance of the synovial 
membranes different osseous concretions, which are often found in con- 
siderable number in these organs, and more frequently in the bursa? 
mucosa;. These concretions do not, however, belong to them exclu- 
sively, for they occur also in the proper serous membranes, particularly 
in the tunica vaginalis testis, and sometimes, although less frequently, 
in the peritoneum, in the pleura, and in those parts of the arachnoid 
membrane, which are blended with the dura mater. 

Most usually, and even almost always, these loose osseous concre- 
tions arise as we have stated. Sometimes they may be loose primi- 
tively, and be developed in the blood, or in another fluid effused into 
the articulation by some external injury, but even then, we have rea- 
son to think that a connection between the effused blood and the syno- 
vial membrane was established before the bone was developed. The 
formation of these concretions in the serous membranes, which are not 
in relation with the bones, proves, at least, that the adjacent extremi- 
ties of the latter have no influence, as Hunter thought, on the change 
of the effused fluid into osseous substance. 

Besides these anomalies, which are somewhat frequent, there are 
others more rare ; such as the development of loose, soft processes 
several lines long on the internal face of the synovial capsule of the 
knee-jomt, of which we have a specimen before us ; perhaps, however 
it is only the first stage leading to the formation of the osseous concre- 
tions which we have already mentioned. 

§ 366. The serous tissue is one of those which has the greatest 
tendency to abnormal repetition in the body. The accidental serous 
membranes are often the foundations of other abnormal formations, 
since they are developed before them, and give rise to them. They 
have been called cysts (cystic), and encysted tumors (tumores cystici), 
and have all the essential characters of serous membranes. They 
constantly form perfectly closed sacs, smooth internally and rough ex- 
ternally. They are produced by mucous tissue, have but few blood- 
vessels, and fulfill the same functions as the proper serous membranes, 
although the substances within them are not always of the same na- 
ture as the serous fluid, and are not always liquid. 

Probably these cysts are not developed, as is generally thought 
mechanically, by an effusion compressing the cellular tissue returning 
again on itself, and thus changing into membrane. Bichat has al- 



300 GENERAL ANATOMY. 

ready contested this theory, by stating that the cysts are most analogous 
to the serous membranes : that the secretion continues to take place 
within them, while compression would probably make them im- 
pervious : that the cellular tissue does not diminish around them, and 
that we must suppose from the hypothesis admitted, that the secreted 
fluid exists before the secretory organ. He thinks these organs are 
formed, -like all others, in the mucous tissue, and that exhalation does 
not commence within them until their structure is completely deve- 
loped. However, it cannot be denied, that the formation of the cyst 
has not been preceded by the effusion of a fluid into the mucous tissue ; 
the cyst, however, does not develop itself, because this fluid com- 
presses the surrounding mucous tissue, but it is formed at its own ex- 
pense ; because it has the power of organizing itself. This theory ap- 
pears very probable on account of the analogy of structure and forma- 
tion existing between the mucous tissue and the serous membranes, 
and because of the pathological phenomena by which the cysts are 
developed. In fact, we not unusually find either in the cavities of the 
normal serous membranes, or in the accidental cysts, an immense num- 
ber of small loose cysts which have no trace of former adhesion, and 
which are filled with a serous fluid, which is generally limpid. These 
small cysts called hydatids(l) (hydatides), are usually surrounded 
with an analogous liquid. They are evidently formed only at the ex- 
pense of the fluid effused in the cavity of the serous membrane, by its 
separation into a solid and a fluid portion. According as this fluid is 
effused into the mucous tissue, or into a serous membrane, the cysts 
which arise from it, unite to the adjacent parts by the surrounding 
cellular tissue, and receive blood-vessels or remain loose and without 
any adhesion. The serous membranes tend more than any other or- 
gan to produce these different kinds of cysts, and even when they seem 
to be developed in the substance of the viscera, as, for instance in the 
liver, which is sometimes entirely destroyed, their development pro- 
bably commences by the portion of peritoneum which covers them, 
for we always find them on its surface, and on some part of their cir- 
cumference. 

(1) These cysts have been termed accpha/ocysts by Laennec, who considers them 
as animals, an opinion which Cuvicr and Rudolphi do not adopt. These naturalists 
and their followers assert, that the accphalocysts exhibit no appearance of vitality ; 
but even when it is granted that they do not enjoy an existence independent of that 
of the liviner bodies in which they occur, they are not the less irritable, like all living- 
parts, and we cannot conceive them otherwise. Besides we have no doubt but these 
vesicular productions are produced by inflammation. Veit long ago proposed this 
theory, (Einige Anmerkungcn iiberdic Entstchuvg derHydaidcn, in Wc\\, Arrliivfur 
die Physiologie, vol. ii., 1797, p. 436,) which G. Jager has since developed. (Beo- 
bachtungen ubcr Hulteiiwurmcr im Menschen und einigen Sdugthicren ; in Meckel, 
Deutsches Archiv fur die Physiologie, vol. vi., p. 495.) He has thus given an ex- 
perimental base of the doctrine of the spontaneous generation of intestinal worms, 
which Rudolphi and Brcmser,assuming reasoning and analogy as guides,have adopt- 
ed as the only one which harmonizes with the present state of our knowledge of animal 
physiology and general physics. In fact, the accphalocysts lead insensibly to the 
proper entozaries by the echinococci, which naturalists no longer recognize as in- 
testinal worms, notwithstanding the special organs with which they are provided, 
and which differ but slightly from the ccenurus, which all herminthologists object to 
place in their catalogue. F. T. 



OF THE SYNOVIAL MEMBRANES IN THE NORMAL STATE. 301 

ARTICLE SECOND. 

SPECIAL REMARKS ON THE SYNOVIAL MEMBRANES. 
A. OF THE SYNOVIAL MEMBRANES IN THE NORMAL STATE. 

§367. The synovial capsules and the bursoz mucosoz(l) present all 
the essential characters of the proper serous membranes in regard to 
form and functions, as Munro, Gerlach, and Bichat had already re- 
marked. But they differ in certain respects so much as to deserve to 
be studied separately ; and they are so similar to each other, that 
we had better embrace them all in a general description. They may be 
termed, collectively, the synovial membranes. The principal characters 
which belong to them all, and in which they differ from the serous 
membranes, are as follows : 

1st. Their relations with the adjacent parts. They are,, at least 
generally, united to bone in a part of their circumference, and this bone 
is cartilaginous where they adhere. They are more closely connected 
with the cartilage than the serous membranes are with the parts which 
they cover. 

2d. Their texture. It is very common to see a particular kind of 
corpuscles which project within their cavity. In fact these corpuscles 
do not exist in all the synovial membranes, nor in all the bursse mucosae, 
but they are found constantly in several. They are very vascular 
masses, and of course very red, especially at the end which is unat- 
tached, slightly hard, of different forms, and they are inclosed in the 
special folds of the membrane, while their loose extremity is almost 
always fringed. Those met with in the articular capsules are usually 
protected from all external pressure, being situated in the depressions 
of the bones. These latter however always press slightly upon them 
when they move. In some joints, as the hip-joint, there is only* one, 
while several are found in others, as in the knee- and the elbow-joints. 

These corpuscles are termed Haver's glands (glandidce mucilagi- 
nosce), because Havers first called the attention of anatomists to 
them, (2) although Cowper had already mentioned some of them. He 
considered their structure to be glandular, and their function to secrete 
synovia. Beside these bodies which project into the cavities of the 

(1) Jancke, De capsulis tendinum articularibus, Lcipsic, 1753.— Fourcroy, Six 
Memoires pour servir a I'hist. anat. des tendons, dans lesqucls on s'occupe specials 
mcntde leurs capsules muqueuses, inMem.de Paris, 1785-17S8.— A. Monro De- 
scription of all the bursce mucosa: of the human body, Edinburgh, 1 rffc8.— Koch and 
Eysold, De bursis tendinum mucosis, Wittenberg-, 17«9.-Nurnberger and Gerk.cn, 
De bursis tendinum mucosis in capite et collo reperiundis, Wittenberg-, 1 / 9^. -Koch, 
De morbis bursarum tendinum mucosarum, Leipsic, 1790.— Rosenrnnller, Vcones ct 
descript. bursarum mucosarum corporis humani, Leipsic, 1799.— Brodic, Pathological 
researches respecting the diseases of the joints, in the Lond. med. chir. trans., vol. iv, 
and v., 1813, 1814. 

(1) Osteologia nova, London, 1691: 



302 GENERAL ANATOMT. 

articular capsules, we find others on their external face in the surround- 
ing mucous tissue. 

It is not probable that the glands of Havers are only masses of fat, 
and that they secrete synovia, although Portal(l) still maintains this 
opinion. The great number of vessels they receive, their situation, and 
the mucous fluid which exudes from them when they are compressed, 
do not authorize us to admit it, as there are several strong reasons 
against it. In fact : 

a. Secretion takes place in the serous membranes, although they 
have no apparatus like that in the glands of Havers. 

b. These bodies exist only in a few synovial membranes : they are 
very rarely found in the tendinous bursae. Synovia however is secreted 
every where. 

c. Their structure does not differ from that of ordinary mucous tissue 
filled with fat. They are not glandular, and although they have a 
considerable volume, we see no appearance of an excretory duct. 

d. We find in some parts in the serous membranes analogous pro- 
longations which are only masses of mucous tissue filled with fat or 
serum ; such are the epiploic appendices of the colon and those of the 
upper extremity of the testicle. 

3d. We cannot question the analogy between the articular capsules 
and the bursae mucosa, although these organs sometimes open into 
each other. This appears not unfrequently in the shoulder-, the hip-, 
and the knee-joint, and almost always occurs in the last two articula- 
tions. The adjacent bursa? mucosa? also frequently open into each 
other, and the masses of fat of the articular capsules often project into 
the adjacent bursae mucosae. It is asserted that this arrangement 
occurs more frequently in old subjects, so that this communication is 
attributed to the destruction of the parts which would otherwise serve 
as a barrier between the two cavities, but this theory is not correct. 
In all cases this communication proves that there is a resemblance 
between the organs, without being attended with inconvenience. Cer- 
tain articular capsules perform at the same time the duties of bursa? 
mucosae, as they adhere to tendons in a part of their circumference, as 
do for instance those of the knee and of the shoulder with the tendons of 
the triceps femoris and the biceps flexor cubiti. 

4th. The nature of the fluid contained in these membranes is always 
the same, even when they communicate together. This fluid is slight- 
ly viscous, and its physical properties resemble the white of an egg. 
In man it has not yet been analyzed : but the analyses of that of the 
ox made by Margueron(2) and Davy(3) do not agree at all in the 
proportions of their constituent elements, but both state that there is a 
great proportion of water, a large quantity of albumen, gelatin, of the 
hydrochlorates, of the phosphates, and of soda. 

5th. The same resemblance exists in regard to their diseases, viz. 
the dropsy, the thickening, and the solidifying of the substance they con- 

(1) Anat. Medicate, vol. i. p. 62. 

(2) Annales de Chimie, vol. xiv. 

(3) Monro, Outlines of anatomy, Edinburgh, 1813, vol. i. p. 79-81. 



OF THE SYNOVIAL CAPSULES IN TltE NORMAL STATE. 303 

tain. There is one, especially the formation of cartilage, and of bone 
within them, which establishes a greater similarity°between these 
organs than between the serous membianes ; for in regard to the fre- 
quency of this anomaly, the bursa? mucosae are more allied to the arti- 
cular capsules than are the serous membranes. 

§ 368. We have already stated the principal modifications in the 
form of the synovial membranes (§ 354). Most of the articular cap- 
sules form simple sacs. However there are some where the 
sacs are double, because an intermediate cartilage is found between 
the corresponding extremities of two bones : this is seen in the temporo- 
maxillary, the sterno-clavicular, and the femoro-tibial joints, &c. 
We usually find only one synovial membrane between two bones. In 
some parts, as for instance in the wrist, they unite a whole series of 
bones blended, if we may so speak, in a single articular surface by 
ligaments stretched from one to another. 

§ 369. The bursas mucosas, with a more complex form (§ 334), 
may be called mucous sheaths (bursa mucosae vaginales), and those of 
a simple form, vesicular bursa (bursa mucosa vesiculares). A general 
remark in regard to both is, that they adhere in a part of their circum- 
ference to a tendon, and by the opposite face to a bone, which in this part 
has no cartilage, to another tendon, or finally to a fibrous ligament. 
On both sides they are intimately united to the organs below them, 
and the rest of their circumference is surrounded by a loose and abund- 
ant cellular tissue. 

The mucous sheaths are cylindrical, and completely envelop that 
portion of the tendon which they touch, and are, properly speaking, 
formed like the serous membranes of two sacs ; the internal sac which 
is smaller surrounds the tendon, while the external sac which is larger 
covers the adjacent parts and blends, opposite the tendon, with that 
portion of bone not covered by cartilage on which the tendon glides. 

They are generally found in the course of long thin tendons, conse- 
quently in the extensors and flexors, especially of the fingers and toes. 
They surround the circumference of the tendon, but they extend a 
greater or less distance along these parts, like the vesicular bursas. 
The tendons of several muscles are frequently enveloped, especially 
in the joints of the hand and foot, in a common sheath, which often 
presents as many folds and divisions as there are tendons, so that 
the general sheath is more or less completely divided into a number of 
special sheaths, from whence several prolongations are afterwards 
detached to accompany each tendon. We also find in particular 
sheaths small firolongations which proceed from that part of their cir- 
cumference which is adjusted to the bone, to the tendon, and are called 
mucous ligaments (ligamenta tendinum mucosa). These processes 
serve only to increase that of the exhaling surface. There are no fatty 
masses fringed upon their free extremity which float in the cavity of the 
mucous sheaths, although fat is often collected in their surrounding 
cellular tissue. 

The mucous sheaths are much thinner and more delicate than the 
vesicular bursae, but they are always surrounded with dense and solid 



304 GENERAL ANATOMY. 

fibrous ligaments, called tendinous sheaths, which are protected by 
osseous canals, while the vesicular bursae are exposed, and only 
strengthened in a few instances by a fibrous substance extended on 
their surface. 

§ 370. The vesicular bursae are round. They never surround a 
tendon completely, but only cover that face of it which is turned toward 
the bone, and consequently form simple sacs which are more easily 
detached without laceration from all the parts to which they are con- 
nected. These characters apply particularly to those which are placed 
between two tendons. These bursae are most generally placed be- 
tween the tendons and the bones, where the former are applied directly 
to the latter, consequently almost always near their insertion. But 
they are sometimes observed on the external face of the tendon ; as 
happens for instance to the tendons of the supraspinatus and of the 
infraspinatus muscles. 

These vesicular bursae are not only fixed to the bones and the ten- 
dons, but they are found also between two bones which move on one 
another, between a synovial capsule and an apophysis of bone, between 
two portions of muscles, and even in the substance of the tendons : the 
last case is perhaps only an anomaly. The third is sometimes pre- 
sented between the two layers of the masseter muscle. The vesicular 
bursaa placed between the coracoid process of the scapula, and the clavi- 
cle is an example of the first. These bursae are properly speaking only 
articular capsules: they present a peremptory argument in favor of their 
identity with the synovial capsules, since they demonstrate that the 
most simple form of the synovial membranes appears also in the articu- 
lar capsules. 

These bursae are mostly simple : sometimes however a small one 
exists within the cavity of a large one, as is the case between the 
tendon of the semi-membranosus and the inner head of the triceps surae. 
So the tendon of a muscle has usually only one vesicular bursa ; but 
in certain cases, as in the masseter muscle, the subscapularis muscle, 
&c, we observe several. 

The vesicular bursae are found more particularly around the large 
articulations surrounded with short and broad tendons, especially in the 
shoulder-joint, the hip-joint, the knee-joint, and the elbow-joint. We 
not only find within many, as the mucous sheaths, ligamentous pro- 
cesses which often form a reticular tissue on their internal face ; but 
also we often see, as occurs in the capsules of the joints, masses of fat 
which float loosely and are more or less fringed on their edge. 

§ 37 1* The synovial membranes are proportionally more extensive 
in the early than in the later periods of life. In age they become more 
dry, firm, and hard, and secrete less synovial fluid. The cellular tissue 
which surrounds them, as occurs in all other parts, is looser in infancy 
and youth, so that at this period theyare more easily detached from 
the adjacent parts. The articular capsules and the bursae mucosae are 
not similar in regard to their number at different periods of life : for the 
number of the former remains always the same, if we except the acci- 



OP THE SYNOVIAL MEMBRANES IN THE ABNORMAL STATE. 305 

dental disappearance of some small capsules, while that of the bursas 
mucosas is always greater in young than in old persons. The com- 
munication existing between several of the synovial membranes also 
differs at different periods of life ; for, in the latter periods of life, the 
bursae mucosae seem to communicate, either with each other or with 
the synovial capsules, more frequently than in young subjects, because 
continued friction destroys them, directly or indirectly, in a portion of 
their extent. 



B. OF THE SYNOVIAL MEMBRANE8 IN THE ABNORMAL STATE. 

§ 372. The anomalies of the synovial membranes are, 1st, their 
absence, which is rare, and of which only the bursae mucosae present 
instances. 

These bursae are sometimes deficient in those parts where we are 
accustomed to find them in the normal state, and are then replaced by 
mucous tissue. 

As to the consecutive and accidental deviations of formation, these 
are the lacerations which occur in dislocations. 

Sometimes we find these organs flabby and distended, either primi- 
tively or from too great an accumulation of synovia. This latter state 
constitutes what is termed hydrops articuli, which is never, unless acci- 
dentally, complicated with the dropsy of the serous membranes. 

The synovial membranes of the joints often inflame ;(1) but inflamma- 
tion in them is much more rare and its progress is generally slower 
than in the serous membranes Its effect is to increase and to change 
the secretion, and to thicken the membrane so that it sometimes ac- 
quires a cartilaginous hardness which extends to the surrounding 
mucous tissue, and is attended with the adhesion of its parietes, while 
its cavity is obliterated, although this latter consequence almost always 
results from suppuration only. When an ulcer is formed, the synovial 
membrane is early or late protruded. 

We may, in accordance with Brodie, consider the change of the 
synovial membrane into a pultaceous mass of a bright brown streaked 
with white, as a disease peculiar to them, which attacks neither the 
tendinous sheaths nor the serous membranes. This is often half an 
inch thick, and gradually extends to all parts of the joint, and becomes 
a destructive suppuration. 

Chronic inflammation with suppuration, and the change which we 
have mentioned, are doubtless the most common of what are termed 
ivhite swellings. In the suppurations and morbid changes described 
under this term, cysts are not unfrequently developed containing fluids 
of different kinds, a remarkable phenomenon, as it is a repetition of 
the tissue in which the disease is situated. 

(1) Koch, De morbis bursarum tendinum mucosarum, Leipsic, 1790. 

(2) hoc. cit., On cases where the synovial membrane has undergone a morbid 
change of structure. 

Vol. I. 39 



306 GENERAL ANATOMT. 

We have already mentioned the cartilaginous and osseous concre- 
tions accidentally formed in the serous membranes ( § 254 and § 270) . ( 1 ) 
The knee-joint is that in which all the changes which have been made 
the subject of inquiry occur most frequently. 

The synovial system is almost the exclusive seat of gouty concre- 
tions. These are hard, uneven, whitish substances, which are effused 
in the form of a fluid during or between fits of the gout. They gra- 
dually harden, and sometimes become large. They have not always 
the same situation, for they are frequently found within the articular 
capsules and the bursae mucosae ; they appear not unfrequently in the 
surrounding mucous tissue, or even between the dermis and the epi- 
dermis. They are usually composed of urate of soda. (2) It would be 
well to examine if the white earthy layer which sometimes forms in 
the place of cartilage destroyed by the gout, be not also urate of 
soda. (3) 

§ 373. Synovial membranes are sometimes developed accidentally : 
this phenomenon is observed in the articular capsules, particularly, 

1st. After unreduced dislocations. In this case, as a new articular 
cavity is formed, even when the old capsule is not torn, which almost 
always happens, a new capsuleis developed, which is smooth within, ex- 
hales synovia, and extends from one bone to another, and is only a 
little thicker, less pellucid, and less brilliant, than usual. 

2d. After fractures. Here the formation of a new capsule is not a 
rare phenomenon. It takes place particularly when the fractured part 
has been moved. Hence it is observed so often after the fracture 
of the ribs ; then the fragments of bone do not reunite ; they become 
round and smooth, like the articular surfaces ; and a perfectly close cap- 
sule is developed around them, which exhales a fluid very analogous to 
synovia. Sometimes Havers' glands are formed in these accidental 
capsules. However, a new capsule is not constantly developed, and 
then the synovia comes from the remnant of the old membrane which 
has been torn. (4) Sometimes also accidental tendinous sheaths are 
formed ; these are more common than the abnormal articular capsules. 
They are real cysts, which do not differ from the others except in con- 
taining a fluid analogous to synovia and often thicker than it. They 
are called ganglions.{b) They are generally considered as abnormal 
congestions of the synovia altered in the bursae mucosae which existed 

(1) See our Pathological Anatomy, vol. ii. 

(2) Wollaston, in Horkel, Archivfur die thierische Chemie, part i. p. 147. — Four- 
croy, Connais. c/iim., vol. x. p. 267. — Moore, Of gouty concretions or chalk-stones, in 
the Med. chir. trans., vol. i. p. 112. Lambert has also found some urate of lime. 

(3) Brodie, in the Med. chir. trans., vol. iv. p. 276. 

(4) Thomson, Lectures on inflammation, Edinburgh, 1813. 

(5) J. Cloquet says (Note sur les ganglions, in the Archiv. gener. de rued., vol. iv. 
p. 232) that the walls of these tumors are usually very thin, semi-transparent, and 
possess capillary blood-vessels; that the liquid they contain is usually diaphanous, 
sometimes very limpid, and sometimes like a reddish, thick jelly, which runs with 
difficulty ; finally, that we not unfrequently find in this liquid a greater or less num- 
ber of foreign bodies, which float loosely, and appear to be real fibrocartilaginous 
concretions. These bodies are white, elastic, and variable in figure ; some adhere 
by a very narrow membranous peduncle, and others are unattached. F. T. 



OF THE CUTANEOUS SYSTEM IN THE NORMAL STATE. 307 

primitively ; but they are found so often in those parts where bursae 
mucosae do not normally exist, that they must be regarded, in many 
cases at least, as real accidental formations. 



SECTION X. 

OF THE CUTANEOUS SYSTEM. 

ARTICLE FIRST. 

OF THE CUTANEOUS SYSTEM IN GENERAL. 

A. NORMAL STATE. 

§374. The cutaneous system (syslema cutaneum) ( 1 ) forms a sac 
which constitutes a general envelop to all the other organs. It may be 
divided into two large sections, the external and the internal cutaneous 
system. The former is usually termed the skin (cutis) or the common 
integuments (tegumenta communia). The second is the system of the 
mucous membranes (membranes mucosae). Although they differ much, 
they are only modifications of one and the same type, as they are un- 
interruptedly continous with each other and in fact are similar in form, 
in composition, in qualities, and in functions. 

§ 375. The external form of this system is that of a sac turned on 
itself, andconsequently double. From this arrangement openings are 
formed both in the upper and in the lower half of the body, by 
which the external and the internal cutaneous systems communi- 
cate and are continuous with each other.(2) These openings gene- 
rally lead into the chief portion of the mucous membranes. The 
latter form a tube which extends the whole length of the head and 
the trunk, and is called the alimentary canal. This canal, which has 
appendages in several parts which give rise to most of the viscera, pre- 
sents above the openings of the mouth and nose, and below that of the 
anus. This part of the internal cutaneous system extends above the 
diaphragm into the cavity of the nose and that of the mouth, and also 
to their appendages, the salivary glands, and continues by the nasal 
canal, with a small process in form of cul-de-sac, comprising the tunica 
conjunctiva and the lachrymal ducts. The mucous membranes of the 
nose and mouth reunite in the pharynx, forming one, which divides 
lower down into two branches, the anterior for the trachea and the 
lungs, the posterior for the alimentary canal. The internal membrane 
of the respiratory system is the largest cul-de-sac presented by the 
internal cutaneous system at its upper part. The posterior branch 
gives off another to the internal ear. Below the diaphragm it furnishes 

(1) Willbrand, Das Hautsystem in alien seinen Verzweigungen, Giessen, 1813. — 
Hebreard, Memoire sur Panalogie qui existe enlre les systemes muqueux et dermoide, 
in the Mem. de lasoc. mid. d' emulation, vol. viii. p. 153. 

(2) A.Bonn, De continuationibus membranarum, 1763. 



308 GENERAL ANATOMY. 

new culs-de-sac, which ramify, and extend to the liver and pancreas. 
Forming then the most internal layer of the alimentary canal, it ter- 
minates in the anus, where itjis continuous with the external cutaneous 
system. 

Besides this general internal cutaneous system, we find others also, 
both in the upper and the lower parts of the body, which only repre- 
sent branches of the culs-de-sac : these are, 1st, the internal membrane 
of the meatus auditorius externus ; 2d, that which covers the internal 
face of the eyelids, the anterior face of the eye, and the lachrymal 
ducts ; 3d, the mammary glands ; 4th, the mucous membranes of the 
genital and urinary systems, which commence by a common opening. 

It is impossible to overlook the gradation which exists from the ab- 
solute insulation of some parts of the internal cutaneous system, to its 
perfect union in a single organ. The general system of the mucous 
membranes of the upper and lower parts of the body, of which we can 
in imagination place the origin in the mouth and intestinal canal, forms 
an uninterrupted cavity. That of the eye communicates with it only 
by a narrow channel, but is not insulated from it, unless after leaving 
the class of reptiles. That of the mouth and of the meatus auditorius 
externus are connected with each other in the membrane of the tym- 
panum, but they do not form one cavity. The membrane between 
the orifice of the genital organs and the anus so much resem- 
bles a mucous membrane in its softness and its abundant secretion 
that we are almost authorized to say it unites the two openings, and 
really blends them in one. Finally, the mucous membrane of the 
mammary glands is the only one which is wholly distinct from the 
general internal cutaneous system. 

§ 376. The whole cutaneous system is then formed of two large 
canals, one narrow and provided'with appendages in form of culs-de-sac, 
the intestinal canal ; the other broader, the common integuments, 
which also possesses some processes in cul-de-sac, which proceed 
internally. It every where presents two surfaces, one of which is 
loose, the other adherent. In the common integuments, the loose sur- 
face is external, and the other internal : the contrary is the case in the 
mucous membranes. Thence it follows that we may consider the two 
sections of the system as two canals, one of which would be folded on 
itself. 

The internal face of the cutaneous system is attached directly or 
indirectly to the muscles by a short cellular tissue. With the external 
system this union is generally direct ; for the aponeuroses are almost 
always interposed between the muscles and its internal face, so that 
the functions of the muscles it covers are rarely in relation with its own. 
With the internal system, on the contrary, it is direct ; for the mucous 
membrane is separated from the muscular membrane only by cellular 
tissue, which is the same as itself in regard to structure and functions. 
The external cutaneous system envelops the voluntary muscles ; the 
internal circumscribes most of the involuntary or hollow muscles. 



OF THE CUTANEOUS SYSTEM IN THE NORMAL STATE. 309 

The loose surface of the cutaneous system everywhere forms folds, 
projections, and depressions of different kinds, which increase its extent 
more or less permanently. 

§ 377. In considering the cutaneous system as a sac folded several 
times on itself, we do not propose to give a history of the origin of the dif- 
ferent parts of the skin, nor to pretend that the different excavations 
are hollowed from without inward, in the midst of a mass which is at 
first solid and homogeneous, so that the upper and lower cavities of the 
intestinal canal meet half-way, while the others not extending so far" 
would still preserve their appearance of cul-de-sac. There are some 
facts which seem to favor this hypothesis. Thus the openings do not 
at first exist, until about the sixteenth week of uterine existence, and 
the upper and lower portions of the intestinal canal which are separated 
from each other not unfrequently form a cul-de-sac, each on its side. 
But these phenomena do not prove that the internal portions of the 
cutaneous system arise from the prolongation of the external inward. 
We can also explain satisfactorily the non-existence of openings in the 
commencement without having recourse to this hypothesis, and by 
admitting that the skin gradually tears in the place where they exist 
by the progress of the formation of the cavities proceeding from within 
outward. This manner of viewing the subject appears more accurate 
than the other, since in regard to the second argument favorable to the 
latter : 1st. The place where the separation exists between the upper 
and the lower extremities of the intestinal canal is not always the same ; 
being often situated in a very distant part ; it is usually connected with 
one extremity only, most frequently the lower, and consequently in this 
case it would follow that the internal portion of the skin is not deve- 
loped except from a single opening. 2d. The upper and the lower 
extremities not unfrequently do not exist, and we find several perfora- 
tions along the passage of the internal portion of the skin. 3d. The 
same arrangement is observed in other processes of the skin, termi- 
nating also in cul-de-sac, as in the urinary apparatus and the genital 
system, where, if we except the closed extremity, the extent of which 
is frequently considerable, it not unfrequently happens that the internal 
and the external parts are perfectly developed, while, according to the 
above mentioned hypothesis, their formation should have been arrested 
where the intermediate partition exists. It is more correct then to 
admit that the internal part of the skin is formed from within outward : 
that it probably takes its departure from several different points ; that 
these join as they are developed and then unite to the common integu- 
ments, making with them an entire whole. 

§ 378. The cutaneous system is essentially composed of several 
layers which may be considered as so many separate systems or only 
as the different parts of the same system. It seems more convenient 
to follow this latter method, because by it we arrive at a better know- 
ledge of the whole system. These different layers are, 1st, the derma 
(derma, corium) ; 2d, the papillary tissue (textus papillaris) ; 3d, the 
fete mucosum (rete Malpighii) ; and 4th, the epidermis (cuticvla.) 



310 GENERAL ANATOMY. 

Bichat has separated the epidermis from the skin, and has considered 
as separate systems several parts described by us (§ 16) as appendages 
to the epidermoid system ; but they are so intimately connected with 
each other, so identified in different parts, that it does not seem proper 
to insulate them. We may then consider all these layers generally in 
the whole cutaneous system, and then particularly in each of its two 
sections. ■ 

§ 379. The derma is the strongest, the firmest part, and the base 
of the whole cutaneous system. Always united to the adjacent sys- 
tems, it adheres to the muscles, in the external skin by its in- 
ternal face, and in the internal skin by its external face. It is white, 
soft, of variable • thickness, having but few vessels and nerves, elas- 
tic, capable of contracting and extending to a considerable ex- 
tent ; it does not possess a high degree of vitality and when destroyed 
is not reproduced. Its consistence and thickness in different parts of 
the body vary very much : generally speaking they are greater in the 
external than in the internal cutaneous system. 

§ 380. The papillary tissue (textus papillaris) which is applied to 
the loose surface of the dermis is in reality only a greater development 
of it, being composed of mucous tissue, of vessels, and of nerves : it has 
the form of small, regularly arranged tubercles which vary extremely 
in the different parts of the cutaneous system in volume and form. 
These tubercles increase the extent of the system still more than the 
folds (§ 377) which support them. The extreme sensibility of the 
cutaneous tissue depends upon them. 

§ 381. The rete mucosum (rete JWalpighii) is a mucous and semi- 
fluid substance having an immense number of capillary blood-vessels. 
It is more readily distinguished from the papillary tissue and the epi- 
dermis in the external than in the internal cutaneous tissue. In this 
tissue and in the preceding the processes of nutrition take place most 
actively. 

§ 382. The epidermis (epidermis, cuticula) is whitish, solid, brittle, 
without vessels or nerves, and entirely insensible. It receives a perfect 
impression of all the irregularities of the layers which it covers. 
We cannot always insulate these latter in the internal cutaneous 
system. It becomes much thicker by friction, and is reproduced en- 
tirely after being destroyed. 

§ 383. We also find in several parts of the cutaneous system simple 
glands, a species of round bursa?, which vary in size and are called 
in the internal cutaneous system, the mucous glands or crypts (glan- 
dule?, s. cryptce mucosae), and in the skin are termed the sebaceous glands 
(glandules sebaceoz). 

§ 384. In those parts where the external and the internal cutaneous 
systems are continuous with each other, the former becomes thinner, 
smoother, finer, and sometimes redder than usual, as in the lips. The 
general characters marking the commencement of the latter are, that 
the epidermis is more easily detached from the subjacent layers than 
in the rest of its extent. 



OF THE CUTANEOUS SYSTEM IN THE ABNORMAL STATE. 31 

§ 385. The cutaneous system envelops all the other organs and 
forms an entire whole; but at the same time it connects the organ- 
ism directly, with external objects, for it continually absorbs materials 
from without and expels them within ; it establishes a limit a sort of 
bridge between the individual organism and the rest of nature It is 
in fact the most important part of all the organs of the nutritive life 
Hence the frequent diseases in this system and its great influence on 
the general health, and the part it takes in all the changes which 
supervene in the organization; hence, also, the close sympathy between 
all its parts, both in the healthy and the diseased states. 

§ 386. The cutaneous system differs in the sexes : it is much 
thicker, firmer, harder, and less sensible in the male than in the female 
It varies at different periods of life, as follows : 

1st. It is less extensive in the early periods of existence, not only 
from the deficiency of some parts, as the extremities, but the intestinal 
canal is shorter and narrower, and the folds appear late. 

2d. It varies in form. At first both the intestinal tube and the ante- 
rior part of the body is open ; there are not two canals opening into 
each other, but only two semi-canals. 

3d. There are at first more vessels and nerves, whence the process 
of nutntion is then carried on more actively. 

4th. It is much thinner in the early periods of life ; 

5th. It is then more loosely united to the subjacent parts ; and, 

6th. There is more analogy between the internal and the external 
portion. 



B. OF THE CUTANEOUS SYSTEM IN THE ABNORMAL STATE. 

§ 387. The cutaneous system reproduces itself after having been 
destroyed, but not perfectly : hence we can always distinguish cica- 
tnces from the true skin. We shall enter into more details upon this 
subject when treating particularly of the external and the internal cu- 
taneous systems. 

§ 388. The congenital deviations of formation in this system are 
either its total deficiency or that of some of its layers, and its super- 
abundance, as seen in the formation of abnormal appendages. The 
accidental anomalies of formation, if we except mechanical injuries 
almost always result from alterations in texture, to which the cutane- 
ous system is very subject, because of the circumstances mentioned 
above (§ 385). Beside those diseases in which it participates with 
other parts, it is often the seat of acute or chronic inflammation. Ac- 
cidental tissues are frequently developed either in its proper substance 
or in the subjacent mucous tissue. Other alterations in its texture, for 
instance ossification, are rare. 



312 GENERAL ANATOMY". 

ARTICLE SECOND. 

SPECIAL REMARKS ON THE EXTERNAL CUTANEOUS SYSTEM. 
A. OF THE EXTERNAL CUTANEOUS SYSTEM IN THE NORMAL STATE. 

I. OF THE EXTERNAL CUTANEOUS SYSTEM IN GENERAL. 

§ 389. The external cutaneous system( 1 ) or the proper skin (cutis) en- 
velops the external surface of the wholebody and forms a close sac which 
possesses its exact form, and is continuous with the internal cutaneous 
system in those parts previously mentioned (§ 375). The skin differs 
from the internal cutaneous system generally, in being thicker, firmer, 
dryer, and less vascular. As we have already remarked generally on 
its form and composition, we have only to describe its component 
layers . 

§ 390. The derma (corium, derma) is a white, solid, and dense tissue, 
which differs in several respects. 

Generally considered, it is composed in great part of layers which 
are very distinctly seen on its internal face and after maceration. 
These layers are produced by a substance very analogous to fibrous 
tissue;(2) their direction is oblique from within outward: they are 
also narrower on their external than on their internal face, and the 
vessels, the nerves, and the hairs pass through the former. This 
laminar tissue is continuous in many places, for instance, in the nucha, 
the back, the abdomen, the sole of the foot, the articulation of the hand, 
and in that of the foot, with the subjacent fibrous tissue which it 
resembles almost entirely, in the palm of the hand and in the sole of 
the foot, by its shining and evidently fibrous texture. But in most of 
the cutaneous tissue, especially the trunk, and in all parts of the limbs, 
its fibrous structure is less apparent and its connections with the sub- 
jacent tissue less intimate. We find no trace of fibres in the derma of 

(1) In addition to the works which have been quoted, we refer to Malpighi, De 
externo tactus organo, in Epist., London, 1686, p. 21-23. — Hoffmann, De cuticulcL 
et cute, Leipsic, 1687. — Limmer, De cute simulque insensibili transpiratione, Zerbst, 
1691. — A. Kaaw, Perp. Hipp, sic dicta, Leyden, 1738. — F. D. Riet, Dc organo tactus, 
Lcyden, 1743. — J. Fantoni, Dc curp. intcgumentis, in Diss. anal. VII. rerwv., 
Turin, 1745, n. i. — Lecat, Traite des sens, Amsterdam, 1744. — Cruikshank, Experi- 
ments on the insensible perspiration of the human body showing its affinity to respira- 
tion, London, 1795.— C. F. Wolff, Dc cute, in N. C. Pelrop., vol. viii. — G. A. Gaul- 
tier, Rechcrches sur Vorganis. de la peau de I'homme, et sur les causes de sa coloration, 
Paris, 1809.— Id., Rech.sur Vorg. cm fane, Paris, 1811.— J. F. Schroeter, Das mcnsch- 
liche Gcfuhl oder organ des Getastes nach den Abbildungen mehrerer berumhten 
Anatomen dargestellt, Leipsic, 1814.— Dutrochet, Observations sur la structure et la 
regeneration des plumes, avec des considerations sur la composition de la peau de* 
animaux vertebrcs, in Journal de physique, May, 1819.— Id., Observations sur la 
structure de la peau, in Journal complemcntaire, vol. v. 

(2) Osiander, from observations on the skin of the abdomen of women who died 
in child-bed, asserts that the fibre which forms the dermis is distinctly muscular 
on the internal face of the skin. F. T. 



OP THE EXTERNAL CUTANEOUS SYSTEM IN THE NORMAL STATE. 313 

the back of the hand, of the sole of the foot, of the forehead, of the 
scrotum, of the labia pudenda, and of the penis, when the substance is 
perfectly homogeneous. 

The dermis varies much in thickness. It is undoubtedly thickest 
on the back of the hand and in the sole of the foot, and thinnest on the 
eye-lids, in the mamma of the female, in the scrotum, the labia pu- 
denda, and the penis. It is thinner in the upper than in the lower ex- 
tremities, and is thicker and firmer on the skull than on the face. 

The dermis under the nails presents a peculiar arrangement, which 
we shall mention when speaking of these last, because all the layers 
of the skin are jointly modified in them. 

§ 391. The skin is often wrinkled or folded, which depends on the 
different states of extension or contraction of the skin and subjacent 
parts, or on other causes. 

The folds of the first kind are produced by the action of the muscles 
or by the diminution of fat below the skin in aged persons, and because 
of its slight degree of elasticity. In fact they result from the circum- 
stance that certain muscles directly beneath the skin, or at least their 
tendons, act frequently while the skin is not sufficiently elastic to con- 
tract and to dilate in the same proportion, or because this membrane 
becoming still less elastic in advanced age does not contract, while 
the fat which distended it is absorbed, and it is therefore folded or 
wrinkled. 

Other folds depend on the papillary tissue of the skin. They 
are very regular, small, compact, and curved. They are very mani- 
fest in the palm of the hand and in the sole of the foot. Each of these 
folds is composed ultimately of two others, for normally their upper 
face is slightly depressed, and the adjacent folds are separated from 
each other by deeper furrows. 

§ 392. Below the dermis, in the panniculus adiposus which it covers, 
wind a great many subcutaneous vessels (vasa subcutanea) : of these 
the veins are very considerable, and are always broader than the deep- 
seated veins. From these cutaneous vessels arise those which are 
expanded in the substance and on the surface of the dermis, most of 
which only pass through it to be expanded in the latter, so that the 
tissue of the skin is not very vascular. The same is true of the 
nerves. 

§ 393. In some places, for instance at the commencement of the 
meatus auditorius externus, at the end of the nose, at the edges of the 
eyelids, around the anus, the vulva, and the nipple, are considerable 
openings from whence comes an oleaginous fluid which hardens 
quickly. These openings lead into small culs-de-sac called the sebaceous 
glands (glandulaz sebaceot). As the whole skin exhales an analogous 
substance, we might be led to think that these glands exist every 
where ; but it is impossible to demonstrate this. Probably the bulbs 
of the hairs should be considered as organs corresponding to them in 
structure and in functions (§ 410), or rather we must regard these 
glands as enlarged bulbs of the hairs which are more developed, since 

Vol. I. 40 



314 GENERAL ANATOMY. 

no hairs come from them, and they are found exactly on the common 
borders of the external and of the internal cutaneous system. It would 
seem also to result from this, that the development of mucous crypts 
in the internal cutaneous system corresponds to that of the hairs and the 
epidermis in the external cutaneous system. 

§ 394. The papillary tissue (textus papillaris){\) of the skin is com- 
posed of small processes situated on the external surface of the dermis, 
particularly on the elevations of the second kind which this latter pre- 
sents : these processes are called papilla of touch (papilla tactus). 
Each elevation presents two ranges of these papillae, which however 
are so connected with each other that they may be considered as form- 
ing but one. Like the eminences on the surfaces of which they are 
seen, they are very manifest in the palms of the hands, in the soles of 
the feet, in the hips, in the glans penis,(2) and in the mammae.(3) 
Their surface is villous. In all other parts they are less distinct, even 
when the epidermis is removed. Even in the preceding regions we 
find none between the elevations in which the papillae of touch are 
situated. 

The latter are composed of nerves and of fine branches of the cutane- 
ous vessels. According to Gaultier, they principally give the color to 
the skin. But this anatomist seems to have confounded them with 
the vascular tissue which covers them. 

§ 395. The external face of the dermis and of the papillary tissue 
is covered with a fine vascular network, composed of numerous central 
points united by many anastomosing vessels which are very apparent 
and regularly arranged. 

§ 396. Proceeding from within outward, we find next to the dermis 
the rete mucosum, or the rele JVLalpighii, a mucous homogeneous sub- 
stance which may be divided into two or three separate layers. (4) 
It has no openings which allow the papillae of touch to communicate 
with the epidermis, but only depressions which correspond to them, 
and within which they are imbedded as in so many sheaths. This 
layer is the principal seat of the color of the skin, since in the negro 
the dermis is as white as in the European,(5) while the rete mucosum 
always presents the peculiar color of each race. Usually it is consi- 
dered single, but we have reason to think it compound. Gaultier assigns 
to it three layers, the first two of which he calls the internal and the 
external tunica albuginea (tunica albuginea interna et externa), 
because of their color, while he calls the third the brown substance, in 
the negro, where it is very apparent. Of these three layers the inter - 

(1) Hintze, De papillis cutis tactui inservientibus, Leyden, 1747. 

(2) B. S. Albinus, De integumentis glandis penis ; loc. cit., lib. iii. c. ix. 

(3) B. S. Albinus, Depapillis mamma et papilla: muliebris ; loc. cit., c. xii. 

(4) B. S. Albinus, Quadam de modis quibus cuticula cum corpore reticulari de 
cuti abscedit, in Annot. acad., Leyden, 1754, 1. i., c. i. De cognatione et distinctione 
cuticula: et reticuli, ibid. c. ii. — De reticulifoveolis vaginisquc quibus papilla contv- 
nentur, ibid. c. iii. — Nonnulla de usu et ratione reticuli et cuticula, ibid. c. v. 

(5) B. S. Albinus. De sede et causa coloris JEthiopum et ceterorum hominum, Ley- 
den, 1737. 



W THE EXTERNAL CUTANEOUS SYSTEM IN THE NORMAL STATE. 315 

nalis the thickest and the external is thinnest: both are white; the 
middle is colored, but less so than the vascular tissue, so that it cannot 
be regarded as the principal seat of color except in the negro Cruik- 
shank has found between the dermis and the epidermis of a negro who 
died from small pox, four layers besides the papillary tissue ; the 'inter- 
nal very thin, a second in which the variolous pustules were developed 
a third which was thicker, the proper seat of color, finally a fourth 
which was whitish, and which he considered the external layer of the 
third. This description agrees pretty well with the preceding. 

The layers, situated between the papillary tissue and the epidermis 
which form this membrane, usually remain united to the epidermis 
when the latter is separated by putrefaction or boiling ; but they some- 
times adhere to the dermis. 

§ 397. The epidermis, or cuticle (epidermis, cuticula),(l) is a mem- 
branous, homogeneous, thin, semi-transparent expansion, whitish in 
the European, light gray in the negro, forming the most external layer 
of the skin, covering the internal layers in every part, and adhering 
to them intimately. It thus presents the same folds and the same in- 
equalities as the latter, and we see on its internal face round depres- 
sions which correspond to the papillae of touch. Its external face is 
smooth, while the internal is very uneven : it is firmly united to the 
subjacent layers ; but in certain cases this union is entirely destroyed 
either during life or after death : it seems to take place by numerous 
small filaments (2) which are perceived very distinctly in the palms of 
the hands and in the soles of the feet, if the skin be immersed into 
boiling water, and the epidermis be detached from the dermis. It is 
however difficult to determine the nature of these filaments. Bichat 
considers them as the extremities of the absorbent and exhalent ves- 
sels; (3) but we have never been able to fill them, even when the cuta- 
neous vessels had been perfectly injected ; and Hunter has succeeded 
no better than ourselves. Might they not have been produced from 
the mucous tissue by the process of boiling ? And if this be false, are 
they really hollow ? 

The same uncertainty exists whether the epidermis be filled with 
holes called pores, or whether it be only thinner in those places where 
these pores seem to exist. Many observers, as Leuwenhocck(4) and 
Bichat, particularly the former, admit that the epidermis is porous, and 
Bichat asserts that the oblique direction of these pores alone prevents 

(1) C.G . Ludwig 1 , Decuticuld, Leipsic, 1735.— Fabricus ab Aquapcndente, De totius 
ammalis integumentis, ac prima de cuticula et its qua supra cuticula sunt, in Opp. 
omn., Leipsic, 1687, p. 438-452.— J. F. Meckel, De la nature de I'cpiderme et du 
reseau qu'on appelle malpighien, in Mem de Berlin, 1753, p. 79-97— Id., JSouv. obs. 
sur I'epiderme et le cerveaudes negres, ibid. 1757, p. 61-71.— B. S. Albinus, Be inci- 
suris cuticula et cutis ; loc. cit., c. iv.—A. Monro, De cuttculd kumana, in Works, 
Edinburgh, 1781, p. 54. — J. T. Klinkosch, De vera natural cuticula et ejus regenera- 
tion, Prague, 1771. — Hermant, De vera natura cuticulce ejusque regeneratione, 
Prague, 1775.— Mojon, Sull' epidermide, Genoa, 1815. 

(2) Hunter, Med. obs. and inq., vol. ii. p. 52, 53, tab. I, fig-. 1, 2. 

(3) Gen. Anat. vol. iii. p. 351. 

(4) Arcan. nat. ep. phys., 43. 



316 GENERAL ANATOMY. 

them from being seen. Others, on the contrary, as Meckel(l) and 
Humboldt,(2) deny the existence of these pores. We have never been 
satisfied of the presence of these openings, and their existence is not 
necessary, since the exhaled fluids can escape very well through the 
thinner parts of the epidermis. 

The thickness of the epidermis is nearly uniform, except in the 
palms of the hands, and particularly in the soles of the feet, where it is 
thicker. In fact, friction increases its thickness, and renders it callous 
in those two parts ;(3) but that this difference has not entirely a mecha- 
nical ori